weet s Tre Bea Sat Pas ee vers WAR DEPARTMENT. REPORT OR A RECONNAISSANCE FROM CARROLL, MONTANA TERRITORY, ON THE UPPER MISSOURI, | TO THER YELLOWSTONE NATIONAL PARK, AND RETURN, MADE IN THE SUMMER OF 1875, BY WILLIAM LUDLOW, CAPTAIN OF ENGINEERS, BREVET LIEUTENANT-COLONEL, U. 8S. ARMY, CHIEF ENGINEER DEPARTMENT OF DAKOTA. WASHINGTON: GOVERNMENT PRINTING OFFICE. 1876. CONTENTS. Letters ot: transm i btaliecu.cnsselseu ade auw se cseusws-ic cic sues pewwie weet veaed base bn aude decetalucandaleableace de Genojal Teportsc22 3 sade stondue meereattn candace Meigen: Aagseece dae nied ora be = bed ga dnedee aaoeARneduateeece beans Orders saccivow sas seis s ve wibacmns seceiceged os Baedide aes sane Sedu Re sdaneten wneereemed hates cues memeawie atmos Composition of the party and instruments employed .......20. 02-022 eee ee cece ee cee eee eee ee cee eee cece eens Saint Paul to Carroll via Northern Pacifie Railroad and Missouri River ......-.2.2. 2-2. .eeeee cee ee eee eee Carroll to Camp Baker, Montana, via Carroll Road 2... 0.222... 0200 cee eee ce eee epee eee cone ce eens cece eee Judith Basin .. 2.22222. 0222.22 eee ee eee eee chariots a Sess n/a Ss ote Ae ape es eetae ated elsy sla ete fare feista we orelsiesreisixe.ar Camp Baker to Rove: Ellis, Montana, via Bridger Pind, Badeuidewe ee see ve ws dee eee rawedinn smenlid en Sscehedicintey Mort Elis:to:the: National Parkes. cecesensted as cuted. gelewat so pes sed zk Be eave oe, See eS rakes eee ne caeebescaas Manmimoth T1ob- Springs.) 222 ce dst luiscae etian anes ee ceed ates ¥ x sew Meme ew eter eee eee sed aa re wrae Mellowsatone Wallac 2d term 54!’ <= —. Latitude = 47 04 03 931 55 00 18 57 34.75 93° 11 30 — 4635 45 50 46 34 55 50” 1» 05" 364.1 88° 38! 27" 4393" hom 8. AR DP VATIG). isaac. aise tase ao ta iessigeetisiaicjeeraesient b Pa Vee Oman oem ee 1 12 59.65 Siu. time at mean noon at this station........ * Sic. interval from mean time of culmination. Retardation of mean on sidereal time...... Mean time of evtUmination of star...... att Error of chron. at time of observation. ...-....22-. 22-02. eee eee eens 1 05 36.10 Time by chron. of culmination...........2.2. 2220-0022 e een eee ee ee eee 2 18 35.75 Clock-time of observation ...........2------acee cence ec cen eee eee ceceee 18 57 34.75 Hourangle:-p; iavsid: Hm 6 sscsc0x sees cme came scczein seam secede w 7 “ar 01. sideves equivalentg@ it B20 .iccccceena we aeguvenspenaees permnenervens 110° 15’ 15” PIM APCs ideas ses icine's cba acwmenemae meee tecin PustaeeetaseeeteeTet Determination of latitude by circum-meridian altitudes. Station, Camp Lewis, Montana.—-Date, July 25, 1875.—Object observed, « Opbiuchi.—Sextant, Spencer Browning, 6536.—Index error, — 20’.— Chronometer, Bond & Son, 202.—Observer, Wood.—Computer, Wood.—Bar., 25i".95.—Ther., 58°. 6W . . +9 Obs’d 2 cir- | Obs’d alti- ; oe ie Mer. dist. Sent he cos l cos D |Red. to mer. gore: Sate a T a 6 alti- pa ee yas ia deduoed . =p: in arc=@. jan alti-| rected for | tudes=a. — a [== 90°4+ D—A. chron. =k rene tudes. index error. So Rh ™ t wa Ww € “a fo} ‘ “ oO t a oO t a“ fo} t “ ° * “ 18 26 45,5 8 00.5 126. 2 27 111 07 30 55 33 35 55 33) «(01 55 35 28 47 03 39 Q7 16. 7 30. 110. 2 08 08 40 34 10 33 36 QT 44, 7 02, 97. 1 53 08 00 33 50 33 16 09 58 28 10. 6 36. 85.5 1 39 08 50 340415 33° 41 20 47 28 36.5 6 09.5 74.3 1 26 09 40 34 40 34 06 32 35 29 14,5 5 31.5 60. 1 10 10 10 34 (55 34° 21 31 36 29 45.5 5 00.5 49. 57 11 00 35 20 34° 46 43 24 30 26. 4 20. 37. as 43 11 20 35 30 34 56 39 28 30 54. 3 52. 29, 4 34 11 20 35 30 34° 56 30 37 31 49.5 2 56.5 17. a 20 11 30 35 35 35 (01 21 46 32 19. 2 27. 12, ef 14 11 30 35° 35 35 (01 15 52 32 47. 1 59. 8. m4 9 11 50 35 45 35°11 20 47 33 %2.5 1 23.5 4. a 5 12 20 36 00 35 26 31 36 34 12.5 33. 5 0.6 s 1 12 00 35 50 35 (16 17 50 34 53. a 0. 3 0 12 50 36 15 35 (41 41 26 35 38.5 52.5 1.5 A 2 12 00 35 (50 35 (16 18 49 36 16.5 1 30.5 4.5 4 5 12 00 35 50 35 16 Pal 46 36 50.5 2 04.5 8.5 a 10 12 10 35 55 35 21 31 36 37 30, 2 44. 14.7 a 17 12 00 35 50 35 16 33 34 38 01.5 315.5 21. 8 24 11 30 35 35 35 (01 25 42 38 35, 3 49. 28.6 o 33 11 00 35 20 34 46 19 48 39 05. 4 19, 36. 6 42 10 50 35 15 34° 41 23 44 40 18. 5 32. 60. 1 10 10 30 35 (05 34 31 41 26 40 47.5 6 01.5 TU. 1 23 10 00 34 50 34 16 39 28 41 39. 6 53. 93, 1 48 09 40 34 40 34 06 54 13 42 10. 7 24, 107.5 2 03 08 00 33 50 33 16 19 48 42 42.5 7 56.5 124, 2 24 08 00 33 50 33 16 40 27 18 43 17. 8 31. 141.8 2 45! 111 07 30 55° 3335 55 33 «(01 55 35 46 47 03 QL MEAD... 0 cee eee e ee eee eee ner ete eee ee cette teeter nee eer e ee ewan e ee nnn nance ens erennenes gate cece ae prise 47 03 37 Oo 4 a hom. &. Semi-diam. App. lat.=1 == 47 03 50. cos 9. 83326 Chron. correction 1 05 36 Refraction 34” Dec. = 12 39 07.4 cos 9.99932 A of * 17 29 10 Parallax a = 55 35 20. cos 0.24785 —_— , 18 34 46 0. 07043 42 RECONNAISSANCE FROM CARROLL, MONTANA, Observation for time. Station, Camp Luwia, Montana.—Date, September 10, 1875.—Object observed, Arcturas —Sextant, Spencer Browning, 6536.—Caronometer, Bond & Son, 202.—Index error, 1/ 20’.—Observer, Wood.—Computer, Wood.—Bar., 25'».75.—Ther., 50°. fe} a “we Double altitudes observed. Corresponding times. Latitude =L = 47 03 50 N. polar dist. = A == 70 10 00 OF ee ho m 8. True altitude=A = 30 02 54 60 40 00 20 02 08 — —— 02. 37. 2m=L+A4A = 147 16 44 03 (06.5 a 03 36. ™m = 73 38 22 04 05. m—A = 43 35 28 04 35.5 59 40 00 20 05 045 log cos m = 9. 4497575 ——— eee log sin (m—A) == 9. 8385388 60 16 00 20 03 35.93 AOR log cos m sin (m—A) = 19. 2882963 log cos L sin A = = 9. 8067069 log sin? §p = 19. 4815894 log sin 3p = 9. 7407947 fe} y aw ap = 33 24 16 p in are = 66 48 32 hom. 8. p in time = 4 2 14.13 RR = 14 09 58.65 Equation of time = True time = 18 37 12.78 Time by chron. = 20 03 35.93 Chron. = 1 26 23.15 Refraction =R = 1 26 Parallax = P = Semi-diam.=Sd = R, P, and Sd = Observed 2alt. = 60 10 00 Index error = 1 20 2 alt. corrected =: 60). 08 40 Altitude = 30 04 20 R, P, and Sd = — 1 Truealt.-A = 30 02 54 log cos L = = 9, 8332634 log sin A = 9,9734435 ll log cos L sin A 9. 8067069 Determination of the latitude by observed double altitudes of Polaris off the meridian. Station, Camp Lewis, Montana.—Date, September 10, 1875,—Sextant, Spencer Browning, 6536.—Index error, —1/ 20’.—Chronometer, Bond & Son, 202.—Observer, Wood.—Computer, Wood.—Bar., 25i>, 75.—Ther., 50°. Observed donble altitudes. Corresponding times. Og ote ot hom. 8 log cos p = 8. 9318631 93 50 30 20 14 34.5 log A = 3. 6HB4192 SL 20 15 31. — 52 00 16 35. log A cos p= 2. 6202829 53 50 18 25. = AVL 54 10 19 53.5 55 10 20 32, Qo 6 ue 55 40 20° 59. Ist term = 6 57.1 56 (00 QL 37. Alt. =A = 46 55 55. 56 10 22 12. Qhterm = 1 O13 5630 22. 38.5 ens 56 40 23 05. Latitude = 47 03 53 57 10 23° 45.5 93 57 30 20 24 17.5 93 54 49 20 20 19.96 1 20 9353 29 46 56 45 50 4655 55 BR POlATIG coos. e sae aie we pea eemew swan eyeade es pamgeke seeEweeeeteete ened Sid. time at mean noon at this station....... Sid. interval from mean time of culmination. Retardation of mean on sidereal time ...-... Mean time of culmination of star ..... Error of chron. at time of observation...................s2ss0ss0eeeee Time by chron. of culmination Clock-time of observation...-. Horan gle, 9; sid tiMs ce essed sadce emcooos mace nbaade ase aseaar Bidereal equivalents 1) alCisenevaeweateans ress cuswansaasamen wn wae PIN BTC sie eseisiee cent cis sieaiaisislsisialaieesale: siniisieiistmed wueecime nee eRe log sin p 9. 99841 log A 3. 68842 log Asin p 3. 68683 log (As in p)? 7. 37366 log a 4. 38454 log tan A 0.02931 log 2a term 1, 78751 2d term 61.3 50” 1) 26m 238,15 88° 38’ 40” 4880" hom 8. 1 13 33.66 1 26 23.15 2 39 56.81 20 20 19.96 6 19 36.85 94° 54’ 13” Station, Camp Baker, Montana.—Date, July 31, 1875.—Sextant, Speucer Browning, 6536.—Chronometer, TO YELLOWSTONE NATIONAL PARK. 43 Determination of the time by observed equal altitudes of the sun’s limb, TO CORRECT THE CHRONOMETER AT NOON. Wood —Computer, Wood. Arnold & Dect, 1362.—Obse: ver, Corresponding times, onion Td a Observed t—t= [Equationof) Mn mee double alti- lapsed | equal alti- Supivon my tudes, timo, tudes = a, chil al et) — ee id - % A.M.=t P. M.==0 tudes. Oo Me hom 8 hom. 8. h. m. Ss. hom. 8. 73 20 00 9 39 53.5 5 00 45.5 40 07. 00 30.5 40 23.5 00 «15. 40 38. 00 00.5 40 52.5 4 59 45.5 41 07. 59 30.5 41 24, 59 16.5 7 18 +9. 60 1 14 21.94 41 37.5 59° O01. 41 33. 58 45.5 42 08.5 58 31. 42 23, 58 (16, 42 33.5 58 Ot. 4 20 00 9 42 53, 4 57 46. 9 41 23. 4 59 15,73 hom 58. pee 7) 16m log A (page 164) = — 9. 4742 log B 9, 2355 16 59 15.73 s&= 37”, 03 log é = — 1. 5687 log 6 — 1.5687 9 41 23. L= 46° 40’ 40” log tan = 0. 0254 logtan D = 9, 5182 26. 40 38.73 ist term = +114, 70 —— —. 1320-19. 36 2d term =e 28, 10 = + 1. 0683 == — 0. 3224 ae 9. 60 a = + 9, 60 = equation of equal altitudes. 13° 20 28. 96 12 06 07.02 1 14 21.94 Determination of latitude by circum-meridian altitudes. Station, Camp Baker, Montana.—Date, July 31, 1875.—Object observed, ©.—Sextant, Spencer Browning, 6536.—Index error, —50’.—Chro- nometer, Arnold & Dent, 1362.—Observer, Wood.—Computer, Wood.—Bar., 23in,20.—Ther., 85°. . 7 . Obs'd 2 cir- | Obs’d alti- : eek arama se Mer dist. 2sin? § p cos J cos D |Red. to mer. cum-meri- tudes, cor- | True alti- sep ane ky 5! Lat. deduced oie, y =p. sin 1’, cus a. inarc= «a. dian alti- | rected for | tudes =a. a ee % | —9004D—A. enrOR: =k. tudes. index error. aps h m. 8. e ia “ a“ ° bd “ ° y “ ° t aw fo} a uw °o i. a“ 110 37.5 9 51.5 190. 8 ( 4 QL} 123 33 10 61 46 10 61 30 OL 61 34 22 46 40 43 1111.5 917.5 169.5 ' 3 52] 122 30 50 61 15 00 30 27 34 19 40 46 11 43. 8 46. 151.0 3 25] 123 34 50 61 47 00 30 SL 34° (16 40 49 12 12. 8 17. 134.7 3 04} 122 32 00 61 15 35 31 (02 34 06 40 59 12 35.5 753.5 122. 2 2 50} 123 35 50 61 47 30 31 21 34 11 40 54 13 01.5 T 27.5 109. 3 2 29) 122 32 50 61 16 00 31° 27 33 56 40 69 13 42.5 6 46.5 90. 0 2 03} 123 37 20 61 4 15 32 06 34 09 40 56 14 19.5 6 09.5 74.5 1 42 122 35 00 6L 17 05 32 32 34°14 40 51 14 47.5 5 41.5 63. 6 1 27] 123 38 40 61 48 55 32 46 34 13 40 52 15 22.5 5 06.5 51.2 1 10} 122 35 40 61 17 25 32 52 34 02 40 63 16 03. 4 26. 38.6 53 | 123 40 20 61 49 45 33 36 34 29 40 36 16 31. 3 58. 31.0 42 122 36 30 61 17 50 33 17 33 59 40 66 17 06.5 3 22.5 22.4 a 31 123 41 00 61 50 05 33 56 34° 27 40 38 17 47. 2 42. 14.3 s 20} 122 37 10 61 18 10 33°37 33°57 40 68 18 15, 2 14. 9.8 ei 13 | 123 41 20 61 50 15 34 06 34 19 40 46 18 45.5 1 43.5 5.8 roy 8} 122 37 50 61 18 30 33-57 34 05 40 60 19 21.5 107.5 2.4 | 3] 123 42 10 61 50 40 34 31 34 34 40 31 19 55, 34. 0. 6 rn 1] 122 38 10 61 18 40 34 07 34 «(08 40 57 20 32. 3. 0.0 3 0} 123 42 00 61 50 35 34° 26 34 26 40 39 20 58.5 29.5 0.5 Ss 1] 122 38 00 61 18 35 34 02 34° (03 40 62 21 33.5 1 04.5 2.3 8 3} 123 42 00 61 50 35 34 26 34 29 40 36 22 16. 1 47. 6.3 q 87 122 38 00 61 18 35 34 02 34 10 40 55 22 44.5 2 15.5 10.0 s 14] 123 41 20 61 50 15 34 06 34 20 40 45 23 23,5 2 54.5 16.6 a 23} 122 37 20 61 18 15 33 42 34 05 40 60 23 55. 3 26. 23.0 ° 32} 123 41 10 61 50 10 34 01 34° 33 40 32 24 32, 4 03. 32, 2 oS 44] 122 36 40 61 17 55 33 22 34° 06 40 59 25 00. 4 31. 40.1 55} 123 40 40 61 49 55 33 46 34 41 40 24 25 30.5 5 O15 49.5 1 08] 122 36 00 61 17 35 33 02 34 10 40 55 25 56. 5 27. 58.3 1 19] 123 39 00 61 49 05 32 56 34°15 40 50 26 21.5 5 52.5 67.8 1 33] 122 34 50 61 17 00 32 27 34 00 40 65 26 52. 6 23. 80.0 1 49 123 37 «30 61 48 20 32 11 34 00 40 65 27 24.5 6 55.5 94.1 2 09) 122 34 30 61 16 50 32. 17 34° 26 40 39 27 57.5 7 28.5 109.7 2 30] 123 37 30 61 48 20 32 11 34 41 40 24 28 29.5 8 00.5 126.0 2 52] 122 32 20 61 15 45 31 12 34 04 40 61 29 11.5 8 42.5 149.0 3 24] 123 35 10 61 47 10 31 01 34° 25 40 40 29 42.5 9 13.5 167 0 3 48 122 30 40 61 14 55 30 22 34 10 40 55 30 12. 9 43. 185. 4 4 14] 123 33 20 61 46 15 30 06 34 20 40 45 130 41.5! 1012.5 204.5 4 40! 122 29 20 61 14 15 61 29 42 61 34 22 46 40 43 MSAD ccc wrein eres a ceiwawin se ped ale seiveieiale slices Serle dire ne enien wdoerewiersiecine dtigmiecietye Ge aibe:Saisisicbe Heelan wieiio ele 46 40 49 f “ h mM. cm J “a Wn 90 40 40 cos 9.83639 Chron. correction 1 14 21,94 Semi-diam. — 15 47.9 4 15 47.9 18 15 05 15 05 cos 9.97758 Equation of time 6 07.02 Refraction — 24.9 — 24.9 ee eeraaey a = 41 33 cos 0.32204 —_— Parallax + 4.2 +4 4,2 108 15 05 a 1 20 28.96 — —_———— 1.3677 0.13601 — 16 086 4 15 27.2 44 RECONNAISSANCE FROM CARROLL, MONTANA, Determriiation of the latitude by observed double altitudes of Polaris off the meridian. Station, Camp Baker, Montana.—Duate, July 31, 1875.—Ref. Circle, Gambay & Son, 212—Chronometer, Boud & Son, 202.—Observer, Wood. Computer, Wood.—Bar., 25'».24.—Ther., 60°. Observed double altitudes. Uorresponding times. Op Ae ot hom &. log cos p = 9. 6527431 log sin p 9. 95098 18 35 49.5 log A = 3. 6804864 log A 3. 68949 36 48. —- - 37 22. log A cos p = 3. 3422295 log Asin p 3, 64047 3757. = 2199" —- 3B 22.5 = log (Asin p)? 7. 28094 38 53, oO i log a 4. 38154 39 23. ist term = 36 39 log tan A 0, 01601 40 32. Alti=A = 46 03 21 —- 720 00 00 41 19.5 2d term = 48 log 2d term 1. 68149 201 22 20 18 41 54. —_—. 2d term 48” = -—— Latitude = 46 40 48 S21 QR 20 18 32 50.05 92 08 14 46 04 07 46 46 03 21 FETEOION «. souseuesss seep eehas EemeRIS: ISRO EoaeeR RS soe 46" Chron. correction . — 1" 12m 759,05 DeGrods ea esccue, s Z 1° Q1/ ux!’ A cadateideees saceaees scent Reeehrayet beyed beam Cemented! 7 4892" hom. 8 AY: TONG TG ese uisrars.citinte otais lepolels g siematmeis ecesinieinnaes 4 SRR EMEE Se naam § aanse este 1 13 05 Sid. time at mean noon at this station....-..- Sid. interval from mein time of culmination. Retardation of mean on sidereal time Mean time of culmination of star....-.- Error of chron. at time of observation aa Pata attest atodeee eyasaharette ana. cesiedis 1 12 35 Time by chron, of culmination .........-...--- 022-2222 e eee eee eee 2 25 40 Clock-time of Observation .22nscea ws ses ceew se ceses wesarersee eames 18 38 50 Hour-angle, p, in sid. time ... : se 7 46 50 Sidereal equivalents in arc... 2.2.2... ee ce ene cee ee eee rec ene eee 116° 42 30” pinare TO YELLOWSTONE NATIONAL PARK. 45 Determination of latitude by cirewm-meridian altitudes. Station, Camp Bakor, Montaua.—Date, August 1, 1875.—Object observed, @.—Sextant, Speucer Browning; 6536.—Index error, — 33//.—Chro- nometor, Arnold & Dont, 1362.—Observer, Wood.—Computer, Wood.—Bar., 25'".20,—Ther., 85°, : in? Obs'd 2 cir- | Obs’d alti- f pinay Mer. dist. asin te cos l cos D|Red. tomer) cum-mori- | tudes, cor- | True alti- a es Lat. deduced sheoa =p. sin 00s & in arc = 2. dian alti- | rected for | tudes=a. zaA. |= 90°+D—A. ki =k, tudes, index error. ea hom. 8. ou u oo ° , bts ° / au ° / “ fo) vi “ ° , “ 114 17, 6 09 74.3 1 41 | 122 05 00 61 02 13 GL 17 40 61 19 21 46 40 44 14 53.5 5 33 60.5 1 22 | 123,08 30 61 33 59 61 17 50 61 19 12 46 40 53 15 40.5 4 46 44.6 1 Ol} 122 06 40 61 03 03 61 18 30 61 19 31 46 40 34 16 26, 4 00 31.4 43 | 123 09 40 Gl 34 34 61 18 25 61 19 08 46 40 57 16 48. 3 38 26. 0 35 | 122 06 40 61 03 03 61 18 30 61 19 05 46 40 60 1725 3 05 18.7 2 25 | 123 10 30 61 34 59 61 18 50 61 19 15 46 40 50 17 49. 2 37 13.4 cory 18 | 122 07 20 61 03 23 61 18 50 61 19 08 46 40 57 18 33.5 1 53 7.0 ot 9] 123 10 40 61 35 04 61 18 55 61 19 04 46 40 61 19 11.5 115 3.0 a. 4/122 07 40 61 03 33 61 19 00 61 19 04 46 40 61 19 40. 46 1.0 3 1] 123 11 10 61 35 19 61 19 10 61 19 11 46 40 54 20 13.5 13 0.0 & 0} 122 08 60 61 03 43 6L 19 10 61 19 10 46 40 55 20 44. 18 0.0 = 0/123 11 10 61 35 19 61 19 10 6l 19 10 46 40 55 21 09.5 43 10 A 1 | 122 07 50 1 03 36 61 19 03 61 #19 04 46 40 61 21 40.5 114 3.0 4] 123 11 00 61 35 14 61 19 05 61 19 09 46 40 56 22 04. 1 38 5.2 et 7 | 122 07 50 61 03 36 61 19 03 61l 19 10 46 40 55 22 36 210 9.2 sg 12 | 123 10 40 61 35 04 61 18 55 6L 19 O7 46 40 58 23 09. 2 43 14.5 a 20 | 122 07 10 61 03 18 61 18 45 61 19 05 46 40 60 23 41. 315 20.7 3 26 | 123 10 10 61 34 48 61 18 39 61 19 07 46 40 58 24 25, 3 59 31.1 o 42 | 122 06 40 61 03 03 6L 18 30 61 19 12 46 40 53 25 02. 4 36 41.5 56 | 123 09 20 GL 34 24 61 18 15 61 19 11 46 40 54 25 38. 5 12 53, 1 1 12] 122 05 30 61 02 28 61 17 55 61 19 07 46 40 58 26 05. 5 39 62.7 1 25 | 123 08 30 61 33 59 61 17 50 61 19 15 46 40 50 26 29.5 6 03 TLY 1 38 | 122 04 40 61 02 03 61 17 30 61 19 08 46 40 57 1 26 48.5 6 22 79. 6 1 48} 123 07 40 61 33 34 61 17 2 61 19 13 46 40 52 24)15 12] 122 38 20 33 38 2) 122 37 47 61 18 53.5 21 61 18 32.5) 38 61 19 10.5) 108 00 04.7 46 40 54. 2! VEG BU Sache Secv re cach iys ase sasd seswea atoms one @adenbia folcisy ate hiale slatare ocaelansenie Mare be Ses Slam diese eaves ee A ed Se bentoesa1d's ame Shara baa erree 46 40 54.4 90 00 00. 0 fo} a “uw ~_ mM &. t “ ¥ aw 18 00 047 App.lat.=t= 46 40 45. cos 9, 83638 Chron. correction 1 14 22,38 Semi-diam.—15 48 +15 48 —_—_- Dec. = 18 00 04.7 cos 9, 97820 Equation of time 6 03. 83 Refraction — 25.2 — 25.2 108 00 04.7 a = 61 18 30. cos 0.31867 — Parallax + 4.2 4 4,2 61 19 21. > 1 20 26.21 —_— ——- = 0. 13325 —16 0% + 15 27. 46 40 44. 46 RECONNAISSANCE FROM CARROLL, MONTANA, Determination of latitude by cireum-meridian altitudes. Station, Camp Baker, Montana.— Date, August 3, 1875.—Object observed, ©.—Sextant, Spencer Browning, 6536. Index error, — 25’.—Chro- nometer, Arnold & Dent, 1362:—Observer, Wood.—Compnater, Wood.—Bar., 25'",20.—Ther., 86°. . +9 Obs’d 2 cir- | Obs’ alti- ; one Oe Mer. dist. Janie coslcos D |Red.tomer.| cum-meri- | tudes, cor-| True alti- gat apy hey Lat. deduced oven Y) =p. sin 1! cosa. |ibare=a.| dian alti-| rected for| tudes =a. 4p A. | | =90°+D—A. ° =k. tudes, index error. =e h. ™m. Ss. ou aa V “ fe} ¥ aw ° t “ fe) v er fo} t aw fe} ra “ 112 59.5 7 20 105. 6 2 26] 122 05 00 61 02 17 61 46 07 61 48 33 46 40 38 13 28.5 6 51 92.1 2 O07 | 121 02 20 60 30 53 46 25 48 32 39 13 53.5 6 26 BL.3 1 53 | 122 06 00 61 02 47 46 37 48 30 41 14 24.5 5 55 68.7 1 35); 121 038 10 60 31 23 46 50 48 25 46 14 51.5 5 28 58. 7 1 2i 122 07 «00 61 03 17 47 07 48 28 43 15 23. 4 56 47.8 1 06} 121 04 10 60 31 53 47 20 48 26 45 16 01. 418 36.3 a 50 | 122 08 10 61 03 52 47 42 48 32 39 16 32. 347 28.1 2S 39 | 121 05 00 60 32 18 47 45 48 24 47 17 00. 319 21.6 23 29 122 08 40 61 04 07 47 57 48 26 45 17 27.5 2 52 16.1 ay 22} 121 05 30 60 32 33 48 00 48 22 49 18 04.5 215 10. 0 2 14 122 09 40 6L 04 37 48 27 42 41 30 18 28, 151 6.7 a 9 121 05 30 60 32 33 43 00 48 09 62 19 00.5 119 3.4 s 4 122 09 50 6L 04 42 43 32 48 36 35 19 30.5 49 1.3 s iL. 121 06 20 60 32 58 48 25 48 26 45 20 00.5 19 0.0 a 0 | 122 09 40 61 04 37 48 27 48 27 44 20 30.5 11 0.0 ia 0] 12t 06 10 60 32 53 48 20 48 20 51 21 52.5 1 33 4.7 3 6 | 122 09 20 61 04 27 48 17 48 23 43 22 37. 218 10.4 # 14} 121 05 40 60 32 38 48 05 48 19 52 23 09. 2 50 15. 8 3 22] 122 09 00 6L 04 17 48 07 48 29 42 23 34, 3.15 20.7 o 29 121 05 20 60 32 28 47 55 48 24 47 24 03. 3 44 27.4 38 122 08 20 61 03 57 47 47 48 25 46 24 36. 417 36. 0 50 | 121 04 50 60 32 13 47 40 48 30 41 25 08. 4 49 45.5 1 03; 122 07 40 61 03 37 47 27 48 30 41 25 50. 5 31 59.8 1 22} 121 038 30 60 31 33 47 00 48 22 49 26 42.5 6 23 30.0 4, 31 122 06 10 fil 02 52 46 42 48 33 8 27 14.5 6 55 94. 0 2 10 121 02 00 60 30 48 61 46 15 61 48 25 46 40 46 Mea nilasaicsdcceiendecasndcaaniestiecunetoues yer ect Sotieah sae cabiee teat ae Sear eaenraesininn Goeeece nk Reims siaerae ace 46 40 44 ° td “ he an. ss ‘ a“ i a“ 90 00 00 App.lat=I = 46 40 40 cos 9.83648 Chron. correction 1 14 238.7 Semi-diam. — 15 483 + 15 48.3 17 29 121 Dec. = 17 29 11 cos 9.97945 Equation of time 5 55.5 Refraction — 25.6 — 25.6 a = 61 48 cos 0.32555 —_— ——. Parallax + 43 4 4.3 107 29 11 1 20 9.2 —_——_ —_— 61 48 33 1.385 0.14148 — 16 09.6 +4 15 27.0 46 40 38 Determination of latitude by circum-meridian altitudes. Station, Camp Baker, Montana.—Date, August 4, 1875.—Object observed, a Ophiuchi—Sextant, Spencer Browning, 6536.—Chronometer, Bon & Son, 202.—Observer, Wood.—Computer, Wood.—Bar., 25'», 22.—Ther., 57°, ' ' A ’ Times of obs. |Mer. dist. ism ie cos 1 cos D |Red. to mer. diy ae by chron. = mae cos a in arc= «a. tuiles: h ™. Ss. v oF a“ : uw oO v “ 18 31 34. 10 12. 204. 2 ( 111 50 40 32 20. 9 26. 174.7 51 30 33 07.5) € 38.5 146. 6 53 00 33 51. 7 55. 123.1 53 50 34 32.5; 7 13.5 102.5 54°50 35 (09. 6 37. 86. 0 55 20 36 11. 5 35. 61.2 é 56 00 37° 14.5] 4 31.5 40. 2 coy 56 50 38 (06, 3 40. 26. 4 a 57 30 38 43.5] 3 02.5 18, 2 a 58 00 39 22, 2 24, 11.3 xe 58 10 40 13. 1 33. 4.7 yer 58 20) 41 00.5 45.5 Tot S 85.1 58 «50 41 53.5 07.5 0.0 3 : 58 20 42 54. 1 08. 2.5 A 58 30 43 51.5] 2 05.5 8.6 1 58 «20 44 385] 2 52.5 16.2 8 58 10 45 25. 3 39. 26.2 S 57 50 46 10. 4 24, 38. 0 iS) 56 40 46 55.5 | 5 09.5 52.3 o 56 20 47 32.5] 5 46.5 65. 5 56 00 48 16. 6 30. 83. 0 55 10 48 53. 7 07. 99.7 54 20 49 31, T 45: 117.9 54 00 50 34.5) 8 48.5 152. 3 52 30 18 51 32. 9 46. 187. 3 111 51 50 ey MSS 2 in 5448 55 57 24 32 55 56 52 1 25.1 55 58 171 102 39_ 08. 6 46 40 51.5 Of hom 8 App. lat.=1= 46 40 40. cos 9.83648 Chron. correction 1 12 35.65 Semi-diam. Dec. = 12 39 08.6 cos 9.98932 * AR 17 29 10.38 Refraction — 32” a = 55 57 cos 0, 25188 Parallax -—— Equation of time 18 41 46,03 1.196 0. 07768 TO YELLOWSTONE NATIONAL PARK. 47 Determination of the latitude by observed double altitudes of Polaris off the meridian. Station, Camp Baker, Moutana.—Date, August 4, 1875.—Ref. Circle, Gambay & Son, 212—Chronometer, Bond & Son, 202.—Observer, Wood.— Computer, Wood.—Bar., 25',22,—Ther., 579, Observed double altitudes. Corresponding times. ne hom 8 log cos p == 9,2947207 log sin p 9, 991395 19 37 17. log 4 = 3, 6893977 log A 3. 689398 37 59.5 —. oe 38 48. log A cos p = 2, 9841184 log Asin p _—3, 680793. 39 26. = 964.1 —_— 39 58.5 log (4 sin p)? 7.36159 40 32. Or Rk a log a 4, 38454 41 17.5 Ist term = 16 04.1 log tan A + 02125 41 53, Alt =A = 46 24 05. ——_— 208 17 00 42 25. 2d term = 58,5 log 2d term 1, 76738 720 00 00 19 42 56. — 2d term 58.5 — — Latitude = 46 41 07.6 10) 928 17 00 19 40 15.25 92 49 42 46 24 51 ~ 46 46 24 05 46’ 1b 12m 35¢.65 88° 38/ 29/ 4891” hom 8. PR POAT IS iai.c:ns cian Soe scieie' ie: ti Saisenaaiosavnsisismsmemdmameeean sas weeeeeee 1 13 08.00 Sid. time at mean noon at this station. ....-. Sid. interval from mean time of culmination. . Retardation of mean on sidereal time...... 2 Mean time of culmination of star -... Error of chron. at time of observation . ........--.--..22. eens eee eee 1 12 35,65 Time by chron. of culmination .........22. 22.00 -2 eee eee eee eee ee 2 25 43. 65 Clock-time of observation .....-. 1.22. ...202 eee eee eee eee eee eee eee 19 40 15.25 Hour-angle, p, in sid. time .-..-...- 20-22 ee eee eee eee eee eee ee 6 45 28 4 Sidereal equivalents in arc. .-.....202 6. ee eee ee ee eee e eee ee eee 101° 22’ 06” p lib OFC aseseenseececusseney Metexeeowsameracuadnieeeracneeeeeeakeeee cs Determination of latitude by circum-meridian altitudes. Station, Camp Baker, Montana.—Date, August 4, 1875.—Object observed, 7 Serpentis.—Sextant, Spencer Browning, 6536.—Index error, — 30”.— Chronometer, Bond & Son, 202.—Observer, Wood.—Computer, Wood.—Bar., 25!»,22,—Ther., 579. Ra . : Obs'd 2 cir- eae ee Mer. dist. Sein" 42 cos Z cos D |Red. to mer.| cum-meri- c fae y =p. sin 1 cos@.|imarc=a.| dian alti- enron: = tudes. h mM. 8. y “a aw “ fo) Z “ 19 23 18.5 4 10.5 34.3 es 80 49 00 24 07, 3 22. 22.3 ri 49 00 24 49. 2 40. 14.0 a 49 00 25 37.5 1 41.5 5.7 8 49 10 26 42.5 46.5 1.2 3 49 10 27 19.5 09.5 .0 iy 49 30 28 01. 32. 6 a] 13 49 30 28 42. 1 13. 2.9 | 49 20 29 19. 1 50. 6.6 ney 49 10 30 04.5 2 35.5 13, 2 EB] 49 00 30 46, 317. 21.2 $ 49 00 31 24, 3 55. 30. 1 g 48 10 19 32 11, 4 42. 43, 4 to) 80 47 40 15.0 80 48 58 30 80 48 28 40 24 14 57 40 23 17 13 40° 23 30 87 04 12 46 40 42 oF au" hem. 3 Semi-diam. App.lat.=l= 46 40 40. cos 9.83648 Chron.correction 1 12 35.65 Refraction 57” Dec. =S§8. 2 55 48.3 cos 9. 99943 KR 18 14 53,22 Parallax = 40 2 20. cos 0. 11824 pee eee eee * 19 27 28.87 . 879 9, 94415 48 Observation for time. RECONNAISSANCE FROM CARROLL, MONTANA, Station, Camp Baker, Montana.—Date, August 5, 1875.—Object observed, Altair.—Ref. circle, Gambay & Son, 212.—Chronometer, Bond & Sons, 202.—Observer, Wood.—Computer, Wood.—Bar., 25'2.30,—Ther., 53°. Double altitudes observed. fo} t “ 86 53 30 720 00 00 806 53 30 80 41 21 40 19 44 Corresponding times. nD an Cc aay am re) o Peo Colon ties Saco S ann na a 18 27 47.6 Latitude = L = N. polar dist. = A = True altitude=A = 2m=L+A4A = m = m—A = log cos m = log sin (m—A) = log cos m sin (m—A) = log cos Lsin A = log sin? 4p = log sin 4p aD = p in are = p in time = KR = True time = Time by chron. Chron. fast = fe} t 46 40 gl 37 40 19 168 27 "ed 13 43. 54 “ 40 33 44 ST 58. 5 14.5 9. 0021000 9. 8410167 18, 8431167 9. 8315447 “19.0115720 9. 5057860 oo: 18 41 37 22 h. m. 2 29 19 44 “ 29 58 8. 31. 87 43.9 17:15 18 27 12, 47.6 1 12 Observation for time. 35. 6 Refraction = R Parallax = P Semi-diam. = $d R, P, and Sd Observed 2 alt. Index error 2 alt. corrected Altitude R, P, and Sd True alt. =A log cos L log sin A log cos L sin A WT a th tl 56. 8 9. 8363878 9. 9951569 9. 8315447 Station, Camp Baker, Montana.—Date, August 5, 1875.—Object observed, Arcturus.—Ref. circle, Gambay & Son, 212,—Chronometer, Bond & Son, 202.—Observer, Wood.—Computer, Wood.—Bar., 25'2.30.—Ther., 53°. fo} t wn Double altitudes observed. ° fe At 68 49 30 720 00 00 10)788 49 30 78 52 57 39 25 30 Corresponding times. hom. 8. 18 51 44. 18 54 39.95 Latitude = L N. polar dist. = A True altitude = A HAL Al 2m=L+A+4A Il ™m m—A Ill log cos m log sin (m—A) log cos msin (m—A) = log cos L sin A = ll log sin? 4p Il log sin 4 p ap p in are pin time KR rll True time Time by chron. Chron. fast = 46 40 70 10 39 25 156 16 78 08 38 42 40 00 30 10 05 35 9. 3130467 9. 7961406 19. 1091873 9. 8098313 19, 2993560 ~ 9, 6496780 oo: 26 30 53 O01 hom. 3 32 14 09 “ 36 12 8. 04.8 59.1 17 42 18 54 03.9 39, 95 1 12 36.0 Refraction = R Parallax = P Semi-diam. = Sd R, P, and Sd Observed 2 alt. Index error 2 alt. corrected Altitude R, P, and Sd True alt. =A log cos L log sin A log cos L sin A WW aT ll uy 58 C. 8363878 9. 9734435 9, 8098313 TO YELLOWSTONE NATIONAL PARK. 49 Determination of latitude by circum-meridian altitudes. Station, Camp Bakor, Montana.—Date, August 5, 1875.—Object observed, « Ophiuchi.—Ref. circle, Gambay & Son, 212.—Chronometer, Bond & Son, 202.—Observer, Wood.—Computer, Wood.—Bar., 25',30,—'Ther., 53°. Times of obs. |Mer. dist. 28"? | 0981 cos D |Rod. to mer,| Observed 2__cir- , = sin 1” ee |) Cum - meridian by chron, =p. an Cou @ inare=2.| sititudes. hom. 8. tou “ “ ° ‘ “ 18 35 33.5 6 13 15.9 os 37 54.5 3 52 29.4 a 38 51. 2 55 16.7 d 39 51. 1 55 12 7 40 52.5 54 1.6 4 | 41 59.5 13 Jacsemeee ss a 40.8 43 10.5 1 24 3.9 4 ‘ 44 18, 2. 32 12.6 ie 45 17% 3 31 24.3 46 41, 4 56 47.8 on | 47 585] 6 12 75.5 ga 18 49 24, VT 38 114.4 oO l 623 26 40 720 00 00 34.1 SEEN SEES 12)1343 26 40 Ml 57 13.3, 55 58 36.6. 33 55 58 03.6. 40,8 55°58 «44.4 102 39 08.7 46 40 24 Oi ee hom 8. App. lat, =1 = 46 40 40 cos 9.83648 Chron. correction 1 12 35.8 Semi-diam. Dec = 12 39 087 cos 9.98932 Equation of time 17 29 10.4 Refraction 33” a = 55 58 cos 0. 25206 ——_——_ Parallax a 18 41 46.2 1, 196 0. 07786 cad Determination of latitude by circum-meridian altitudes. Station, Camp Baker, Montana.—Date, Augnst 5, 1875.—Object observed, » Serpentis.—Ref. circle, Gambay & Son, 212.—Chronometer, Bond & Son, 202,—Observer, Wood.—Computer, Wood.—Bar., 275», 30.—Ther., 53°. : , ; Times of obs. |Mer. dist. |? 9° 4?| cos tcos D allt Sige by chron. =p. sinl’ |-—Cosa y =k cos @ tudes. h, m8. mens - we a 19 23 15. 4 14. 35.2 4 ( 24 53.5] 2 35.5 13. 2 fy 25 55. 1 34 4.8 4 26 55.5 33.5 0.6 ig 27 56.5 27.5 0.4 po 28 54. | 1 25. 3.9 | a: 30 24.5] 2 55.5 16.8 $ 19 31 34. 4 05. 32.7 |) 8 8) 646 29 00 13. 45 80 48 37.5 “40 24 18.7 56.4 40 23 22.3 “40 23 34.1 of # hom 8% App. lat.=1= 46 40 40 cos 9.83648 Chron. correction 1 12 35.8 Semi-diam. Dec. = 2 55 483 cos 9.99943 xR 18 14 53.2 Refraction 56.4 a = 40 23 20 cos 0.11824 —_—— Parallax See 19 27 29.0 . 879 9, 94415 ‘TW 50 RECONNAISSANCE FROM CARROLL, MONTANA, Determination of the latitude by observed double altitudes of Polaris off the meridian. Station, Camp Baker, Montana.—Date, August 5, 1875.—Ref. circle, Gambay & Son,.212.—Chronometer, Bond & Son, 202.—Observer, Wood.— Computer, Wood. —Bar., 25!". 30,—Ther., 53°. Observed double altitudes. Corresponding times. aes am h. mm. 8. log cos p = 9.3227046 log sin p 9. 99018 19 34 18.5 log 4 = 3. 6893977 log A 3. 68940 34 48, —_-—- —_—_—- 35 31 log 4 cos p= 3. 0121023 log Asin p 3. 67958 36 30. = 1028.3 —_— 37 06.5 —_—__— log (A sin p)27. 35916 37 37.5 oj: " log a 4, 38454 38 08.5 1Istterm = 17 08.3 log tan A .02091 38 44, Alt.=A = 46 22 43.2 —_—_—_—_- 207 50 00 3917.5 2d term 58. 2 log 2d term 1.76461 720 00 00 19 39 57.5 ———_— 2d term 58.2 pa S eri d Soe Latitude = 46 40 49.7 10) 927 50 00 19 37 119 92 47 00 46 23 30 46.8 46 22 43.2 Refraction 46.8 Chron. correction .. 1h 12m 35%.8 Dec 88° 38/ 29/7 Azecexprosssis sane cea caraeneamasiuess ocncceensaccvek cexesevesmeeecseks 4891!" hom s. AE POLATIS ssc sete ac ccaneecdces oh mee Gaon wen awemscrstnsessieese ue mseaie 1 13 08.76 Sid. time at mean noon at this station... : Sid. interval from mean time of culmination Retardation of mean on sidereal time .... Mean time of culmination of star ........ Error of chron. at time of observation ........22.. eee ee eee ee eee eee 1 12 35.8 Time by chron. of culmination.......... 0.00022 cence ence ce cee rene eee 2 25 44.56 Clock-time.of observation sais ecccccesncsesis ceed ec cccce nese eusimencts « 19 37 11.9 HMoursan gle, im Mean: tM Os seis asreiesinnsecreis soarreiee sciesyeaig cae siete earoee 6 48 32.66 Sidereal equivalents in ate. cas ssccewcarsceenscecscesess coe sea veces 102° 08’ 10” Pr AMAT Cs, < aiuiciaikycejominaleins sic cisiacuseaicceGieeleae Wiafciala/e.aaarctovataceataticie ealsiaiein cate Determination of the latitude by observed double altitudes of Polaris off the meridian. Station, Camp Baker, Montana.—Date, August 5, 1875.—Soxtant, Spencer Browning, 6536.—Index error, —60’.—Chronometer, Bond & Son, 202.—Observer, Wood.—Computer, Wood.—Bar., 25's, 30.—Ther., 53°. Observed double altitudes. Corresponding times. Oe i ot hom 8. log cos p = 9. 4822605 log sin p 9. 97901 92 30 30 19 11 51.5 log A = 3. 6893977 log 4 3. 68940 31 10 12 44 —_— 31 20 13° 24.5 log 4 cos p == 3, 1716532 log Asinp 3.66841 3L 50 14 (00.5 = 1484.8 —_—- 32 10 14 40 —— log (A sin p)? 7. 33682 32 40 15 23 Oo fut log @ 4, 38454 33 20 16 10.5 Istterm = 24 44.8 log tan A 0.01896 34 00 16 49.5 Alt= A = 46 15 00.7 — 34.15 17 21.5 2dterm = 55. 0 log 2d term 1. 74032 92 34 35 19 18 06.5 —_—— 2d term 50”. 0 ——_—— —— Latitude = 46 40 40.5 92 32 35 19 15 03,25 1 00 92 31 35 46 15 47.5 46.8 46 15 00.7 Refraction :sccoccsacoswponacnaedy seccasexese cess se erseseseeseescews 46.8 Chron. correction 1h 12m 35%. 8 ANC Citta cierete ocala nisyatecsise 2:3, 88° 38/ 290” LS cs Beanie aigcavaca aie veissairere eva talc och ararea a aid eaaienae aleve vaneicide Sip staee hese eats ok eae 4891” hom. 8. BY POLIS ois wise ’sainers ataeneclasemente vest gactslocionensinessdeinaacingsisciexa 1 13 08.76 Sid. time at mean noon at this station.......-2..-2. 2-2 .ee eee eee cee Sid. interval from mean time of culmination ....-.....2..22.-00.-eeee Retardation of mean on sidereal time .-.-.. disGerUserenseaoMe manele Mean timo of culmination of star * Error of chron. at time of observation ...... 022.22 eee eeee ee eee ences 1 12 35.8 Time by ‘chron. of culmination s.. 8S 8 ie i Sty my, =A Nr’ 35) “p i UR a ane, Sus aoe go : iy 98 RECONNAISSANCE FROM CARROLL, MONTANA, itself previously built up, and also to a less extent carrying away the older deposits. It acts alone, unaided by any minor tributary streams; for they are dry except in the early season. Even during the summer, however, the channel is constantly changing. The mud-and-sand bars which are everywhere formed do not long retain their positions, but are moved on down the river and heaped up again in other places. Thus the process is one of gradual transferral down the stream ; the solid matter going to make one alluvial bank after another until it is finally deposited in the Gulf of Mexico. It is interesting to note, in this connection, the explanation recently given by Prof. James’ Thomson (Proc. Royal Society, 1876) of the origin of the windings of rivers in alluvial plains. He shows that, upon hydraulic principles, the velocity of the stream must be greater on the inner bank than on the outer, and yet, as shown here, the wearing away takes place upon the outer bank, and the deposits are made on the inner bank. This is in part due to the centrifugal force, which tends to make the surface-water move away from the inner bank, while its place is taken by a partial upward current of the bottom water retarded much by friction. This current moves obliquely toward the inner bank, and serves to protect it from the rapid scour of the stream-line. On the outer bank, however, there is a tendency of the rapidly-moving surface-water, unimpeded by fric- tion, downward against the solid bank; this it tends to wear away, the worn substance is carried down to the bottom, where the oblique current spoken of carries it toward the inner bank. Sooner or later it will reach this point, and more or less of it will find a resting-place. These principles find an application in the flow of the Missouri through its alluvial plain. It is on the outer bank of the successive curves of the river that the wear is greatest, and that the river has forced its way up to the older bluffs, while on the inner bank the deposits are being made, more or less, all the time, sand or mud, or both, according to the relative velocities of the different parts of the stream. As has been remarked, the work of the river in summer is destructive, and no additions are made at this time to the height of the alluvial banks. In spring, the case is very different, and it is at that time that the chief deposits of alluvium are made. The river is then full, the snows all over the wide area drained by the Missouri are melting, rains are frequent, and a vast amount of material is brought in from the surrounding country. The amount of solid matter held in suspension at this season is enormous. In floods, the waters rise many feet, overspreading the lower alluvial ground, aud in subsiding and evaporating they deposit their load of sand and clay, sometimes covering a well- grown and fertile plain with a bed of alluvium afoot and more in thickness. This sometimes takes place for a number of successive years at the same points, as is shown by the fact that the roots of trees which must have been close to the surface of the ground when they commenced to grow were often seen buried beneath from four to six feet of allavium. We could of course only observe this on the very edge of the bank, where the water had removed a part of the old alluvium, expos- ing to view the roots, and that part of the trunk which had been buried. Some of these trees were quite small, not more than 3 or 4 inches in diameter, and most of them were still living; thus indicating how rapidly such depos- its as those referred to are made. The trees were mostly cottonwoods and elms, species of rapid growth. That these deposits are made very rapidly is also shown by the thick Jayers to be noticed in any section of a bank so deposited, sometimes a foot or more, perfectly homogeneous. It is interesting to note the great variation in the height of the perpendicular alluvial banks. From point to point, in some cases, it is only three or four feet; in others twenty-five feet or more. This depends obviously on the strength of the current, and the extent to which the water is backed up. It bears upon the general subject of river-terraces. Not infrequently we observed a second terrace above, or rather a long line of high cut bluffs separated from the stream by another alluvial plain (see figure 3). This is all of recent origin, and merely means that the river stopped washing away the bluffs here, and commenced to fill up at its foot. The energy of the stream is at all times directly proportional to the amount of the descending TO YELLOWSTONE NATIONAL PARK. 99 water; aud hence is immensely greater in spring than in summer. This energy is probably all expended in overcoming friction, and in carrying the load of solid matter. The difference in the amount of detritus held in suspension by the stream in early July and in late September was very marked—at the latter time the stream seemed to have to a great extent cleared itself. This is doubtless due to the diminished volume of the water, in consequence of which the carrying power of the stream was so much diminished. , sec map) is an exposure of blue laminated clays, with abundant concretions, probably the Fort Pierre Group again, though here 600 feet above the highest exposure observed below, and 400 feet above the sandstone identified as No.5 (a4, on map). The elevation is due to the uptuarn- ing of the mountains, involving both members of the Cretaceous alike. From here we made the ascent of Cone Butte. The immediate foot-hills, and indeed those at some distance from the peak, are made up of the talus from the mountain as far as the surface- exposure goes. Loose blocks of the trachyte, which forms the mass of the mountain, have been spread over the surrounding country to a remarkable extent, and the smaller fragments were found abundantly within a mile or two of Crooked Creek; that is, having crossed Box Elder Valley, Cone Batte is, as has been intimated, a trachytic hill, and according to the readings of our aneroid it is 2,200 feet above Box Elder, and 3,400 above the Missouri River. This is about the average height of what are called the Judith Mountains, though there are several points which are probably a little higher. The summit of Cone Butte commands an extensive view over the prairies to the north. The Little Rocky Mountains and the Bear’s Paw Mountains, though far in the distance, are the most conspicuous points to be noticed. Its commanding position is well appreciated by the Indians who use it as a lookout, for which it is most conveniently situated. A shelter which we found on the summit, formed of large flat blocks of trachyte resting upon the spreading branches of a stunted pine-tree, had doubtless been used as a resting-place by many an Indian scout. Cone Butte is itself a conspicuous object from all the surrounding country, even as far north as the Little Rocky Mountains; its perfectly conical shape being very striking from any point on the Carroll road. Viewed from the west, the sides of the cone are broken, and not so symmetrical as shown in figure 6. The slopes are covered with loose blocks of trachyte, and at some points are TO YELLOWSTONE NATIONAL PARK. 105 ®. precipitous. The angle of the cone is about 40° or 41°; indeed, it is so steep, and the loose blocks of trachyte furnish so insecure a foot-hold, that, were it not for the trails made by the mountain- sheep ascending and descending, it would be no easy task to climb it from the west side. The mineralogical character of this trachyte deserves to be described a little in detail, as it may be taken as a type of the variety which occurs most widely in these mountains. It is in gen- eral of uniform texture, hard and firm, though occasionally showing minute cavities containing quartz crystals as a secondary product. It breaks on weathering into the large thin slabs which cover the sides of Cone Butte. The main constituent of the rock is a triclinic feldspar, as revealed by a thin section under the microscope, though occasional crystals of orthoclase of greater size may be observed. Hornblende follows next in order, the crystals being very distinct; and, further than this, magnetite plays an important rdle—this is distributed more generally than is common in similar rocks, and is seen by the microscope as extremely minute grains, whose metallic character is revealed only in reflected light. These particles of magnetite have suffered alteration to a considerable extent, and the feldspar is often stained red and yellow in a ring about them by the oxidized iron. It is to this alteration that the peculiar red color of the talus on the sides of the hills, as seen from a distance, is undoubtedly due. A critical examination shows that a little quartz is also present; but, as it was often otherwise noted in minute cavities, it may be questioned whether it is not merely a secondary product. The descent from Cone Butte was made by way of the deep ravine which separates it from the trachytic hills to the south. The white trachyte is carried down nearly to the gap, where (see fig. 7) we passed a transverse dike, east and west in direction, of a hard green trachyte, with a cubical fracture breaking into large angular blocks, in striking contrast with the loose slabs of the other trachyte which cover the slopes of Cone Butte. This is probably a later dike, subsequent to the formation of the other hills. This trachyte, as well as that of Cone Butte, was found in frag- ments abundantly over the prairie, even to a distance of fifteen miles from the mountains. It is characterized by large crystals of a glassy orthoclase, which give it a porphyritic structure. Under the microscope, these crystals are found to be more or less clouded, in consequence of incipient alteration: this is also shown by the indistinct colors obtained in polarized light. Accompanying the large crystals of orthoclase are smaller thin-bladed crystals in large numbers. The other essen- tial constituent is the hornblende, which is seen in simple distinct prisms: it has a deep-green color, and is strongly dichroic. No quartz was observed. The most interesting feature of the rock eg SSS SS ee ——S EOS ss Sh ee ee = Se ae 6S ees AS ey oe is the green base, which, under a low magnifying power, seems to be without structure, but, when magnified highly, is resolved into countless minute, acicular crystals, jumbled together in a con- 14 Ww 106 RECONNAISSANCE FROM CARROLL, MONTANA, fused mass. They show very little color in polarized light. They may be zeolitic; but a chemical analysis, which the circumstances do not now admit of, would be required to settle the point. In the ravine spoken of, 355 feet below the summit of Cone Butte, we were surprised to find a series of slates and sandstones. The cut (Fig. 7) will give some idea of the relations of the rocks, it being a sketch taken from a point below to the west. The total width of the gap is about 70 yards; the trachyte rising abruptly on both sides. The trachyte of the hill to the south is quite similar to that of Cone Butte. The section in the gap is as follows: Coarse ferruginous sandstone, vertical ........-0.00ce eee eee eens igi eugene Y 3 feet. Hine blue shale. vertical: ¢c.02 vucupun we sa wanda lew nate dan denne ale ews eked 20 feet: Slate, sometimes shaly, sometimes a good slate, and very sandy, in layers; color whitish and yellowish; dip 70° south .... 2.2... 02.222 :0eeeeeee ea ie ae eee aw 180 to 200 feet. The strike of these slates is east and west. The age of these rocksis uncertain, as the only fossils found in them were some cycloidal fish- scales, with occasional impressions of fish-vertebrae and spines, which were quite numerous in some layers in the slate. It is hardly to be doubted, however, that they are Cretaceous; and the position of some rocks, also containing fish-scales and probably identical with these, observed at another point, as noted below, suggests that they are probably Upper Cretaceous, perhaps No. 5. The present position of these slates is very remarkable: they lie far above (about 600 feet) the rocks visible in the hills below, and doubtless owe their elevation to the eruption of the trachyte, having been squeezed up between the two great masses of igneous rock. They show little trace of the influence of heat upon them. The hills to the south and east, forming the eastern extremity of the Judith Mountains, are, as far as observed, trachyte. Black Butte, or Buffalo Heart Mountain, was not visited; but its posi- tion and similar appearance show that it is also eruptive, probably exclusively so. The sand- stones dip away from it even more distinctly than from Cone Butte. It may be remarked here that the trachytic hills are very distinctly marked in appearance, and may be recognized with certainty even ata considerable distance. Their sides are covered with the loose blocks of the rock, and have a distinct reddish color, due to the oxidation of the iron which exists in considerable quantities in the trachyte (see description), which is quite conspicuous and characteristic. West of Cone Butte (see e, fig. 5), there is a break in the hills, and alow pass called “ Ross’s Cut-off” gives passage to frequent Indian parties. It is free from timber, and of gradual slope, so that upon one occasion wagons were brought through without serious trouble. It is from this low pass that Box Elder takes its rise. In this gap, the observations made were unimportant; the rocks being mostly covered up with soil and grass. It was interesting, however, to note that the even, gradual slope of the terrace before mentioned extends quite into the pass, with the same character well preserved. At e, (Fig. 5,) just on the edge of the hills which rise on the west side of the gap, a series of black shales were ob- served, vertical, and with a strike nearly north and south. These hills at g and to the south are all trachyte. We crossed. them at one point, dragging our horses over the loose talus, much to their and our own discomfort, and found the height a little less than that of Cone Butte. On their west- ern side, the trachyte shows itself in a series of columns, which are very regular and well formed; much more so than is common in this rock. This trachyte differs somewhat from the others described in the larger proportion of hornblende present. As before, the orthoclase appears in distinct crystals of large size, and the triclinic feldspar in thin-bladed fragments. The whole has a pasty base. A little valley, in which rises a small stream of cool water, lies just to the west, and. on the other side is a high limestone bill (at k), the only exposure of the older sedimentary rocks which we met with in this part of the hills. This limestone rises in a series of sharp ridges, very distinct, and seen from a distance as a number of white lines running up the sides of the hills. It dips 50° northeast; the strike being northwest. The upper layers are white, semi-crystalline, and very profuse in flinty fragments. These are exposed by the weathering, and, on the surface, the rock has quite a coralline aspect. Lower layers are firmer, blue, and also cherty, though not to the same extent as those above. A very careful search showed that fossils were very rare, though a few were found, enough to deter- TO YELLOWSTONE NATIONAL PARK. 107% mine the age of the rock to be Carboniferous. The following is a list of the fossils obtained at this oint : : Crinoidal remains too indistinct to be identified. Terebratula or Cryptonella. Spirifera (Martinia) lineata, Martin. Spirifera centronata, Winch. Orthoceras? ??, possibly filling of outer chamber. Spirifera centronata, Winch., was the most abundant and characteristic form noticed here. The thickness of these limestone beds must be very considerable; at least 300 or 400 feet were seen on this side of the hill, but as we were unable to foliow them farther, we cannot venture to estimate their whole extent. This limestone is intersected at one point by a ridge of hard trachyte. On the other side of the little creek valley, the limestone also appears, containing here only a few imperfect crinoidal stems. Here it is apparently overlaid by a sandstone which has all the appearance of dipping under the hill, or, in other words, is overlaid by the trachyte. The outlying hill, f, is made up of sandstone, or a sandy slate; its summit is 1,200 feet above Box Elder, and hence a thousand feet lower than the adjoining trachytic hill. The observed thickness of this slate is 200 feet; dip 10° a little east of north, and strike nearly east and west. It can hardly be conformable to the limestone described; but the eruption of the trachyte, which doubtless accompanied the elevation of the mountains, has very much complicated the relations of the beds.. This slate contained large numbers of poorly-preserved fish-scales, which would seem to show its probable identity with the elevated slates in the ravine behind Cone Butte. Further than this, its position seems to suggest that it may be nearly parallel with the sandstones near Cone Butte, which are, as has been stated, Upper Cretaceous. No trace was seen at this point of any rocks between the Cretaceous and the Carboniferous limestone. gu bop FROM BOX ELDER TO CAMP LEWIS. The road from Box Eldez to Camp Lewis follows along the foot of the mountains, but at such a distance from them that very few observations could be made. The character of the country is much better than that nearer the Missouri, but cannot be very highly praised. The Judith Mount- ains give rise to several running streams, which occupy wide valleys, and the region seems well adapted for stock-raising. Near Armell’s Creek, a mile to the north of the road-crossing, gray clays are conspicuous, forming high bluffs with perpendicular faces, quite different from anything seen near Crooked Creek. This exposure was visited later, on the way to the mouth of the Judith River, but yielded no fossils, and its age is therefore uncertain. It is probably, however, near the top of the Cretaceous. Our road approached quite near the mountains at Bald Butte (see m on map), and here,and at several points beyond, we observed a considerable thickness of a soft white sandstone, fine-grained and even-textured, but without fossils. It is in very thick beds, and weathers out in vertical walls, taking fantastic shapes, which are like those of the “Quader Sandstein” of the Saxon Switzer- land. This is undoubtedly Upper Cretaceous. From this point, the road bears away from the hills again, crossing the divide between the Musselshell and Judith Rivers, and passing between the Judith and Moccasin Mountains. As has been before remarked, the dark clays of the Fort Pierre Group are seen again south of the Moccasin Mountains and just before reaching Warm Spring Creek. At this point, there was a considerable exposure of these beds, and, although no fossils were collected here, the characteristic features of the deposit were unmistakable. Farther on, a cut bank on the creek gave the following section : Yellow clays, somewhat sandy ....-.----..-----+-e+eeeee di Bee Sawing es ails 20 feet. Hard gray shaly clays Seen. ..----.--- 6-2 ene eee ene ce eee eet e tere eee eeee 20 feet. These beds had a very slight dip a little cast of north. The Moccasin Mountains we were unable to visit; but their appearance, as viewed from vari- ous points on the road, and again from the northeast, indicated that, like the Judith Mountains, they are largely trachytic. Camp Lewis is situated on Trout Creek, or Big Spring Branch, as it is sometimes called, which 108 RECONNAISSANCE FROM CARROLL, MONTANA, is the largest branch of the Judith River. This is a wide stream of clear, very cold, water, which takes its rise in a spring about five miles from where the camp is situated. The immediate valley of the stream is covered with excellent grass, and when the country becomes safe from the incur- sions of hostile Indians—far from being the case at present—it must prove of high value for settlement. About Camp Lewis there are considerable deposits of red clay. This is the case on both sides of the stream, but most conspicuously on the east bank, where the bluffs for a considerable dis- tance are of a deep-red color. It is rare to find any exposures of the beds which give rise to these red slopes. In general, they are so washed down that only the red surface-deposits are seen. In some ravines, however, on the east bank of Trout Creek, we found the hardened red clays in place. No fossils could be discovered, though they were searched for with care. These beds seemed to be somewhat irregular and of rather local character. In the place where opportunities for observa- tion were most favorable, we found 10 feet of red laminated clay, underlaid by a gray shale and overlaid by a sandy slate of a brown color. A little farther north, other layers of sandstone were observed, and beneath these some very thick bedded sandstone deposits; the red clays running out entirely. There was nothing to settle positively the age of these deposits. Except in color, they do not resemble the “red beds” of the West, generally referred to the Triassic; and as similar deposits were seen on the slopes of the Snow Mountains, twenty-five miles distant, overlying sandstones containing Cretaceous fossils (the same was true elsewhere), as noted later, it is more than probable that they are all Cretaceous in this vicinity. From this point, on our return journey, we made a detour and crossed the west end of the Judith Mountains; and, as we have just stated our observations in the neighborhood of Cone Butte, it may be interesting to add the others in this place. Passing on from the red beds just mentioned, we crossed a low divide, and came down into the wide valley of a branch of Trout Creek, passing over some more red clays at a little higher level than those seen before. From here, our course was about north; our objective point being some white limestone bluffs conspicuous on the summit of the range. The foot-hills first passed over consisted, as indicated by one or two rock-exposures, of a brown, firm sandstone, in which no fossils were found. It had a dip of 20° away from the hills. These hills, in both directions, are covered with timber and grass, and the rock is rarely seen on the surface. The limestone bluffs (1, fig. 5) were reached without much clue to the structure of the inter- vening country having been gained. This limestone stands up in a series of high buttresses, which, with their vertical fronts, are quite conspicuous objects. They show no evidence of stratification or structure. The rock contains occasionally masses of flint, though they are not so conspicu. ously cherty as those seen near Cone Butte. Some few fossils show that the rock is of Carboniferous age. The following is a list of those obtained : 1, Zaphrentis centralis, Ev. & Shum. 2. Syringapora mult-attenuata, McChes. 3. Stictopora, sp. 4. Spirifera centronata, Winch. On the hill to the west of this, a broad band of stratified limestone is exposed, in which some similar fossils were found. This same band apparently appears again on the north side of the bill, but here with a changed dip, northwest instead of southwest, pointing to a fold over at this point. We crossed the higher ridge here, from which we could see off to the east, noting, as before, that the hills to the north are mostly trachyte, while those behind them to the south are as uni- formly limestone. Near the source of Deer Creek, we descended into a broad, green meadow, quite surrounded by the hills. At one point, a patch of bright-red soil suggested a return to the red clays before seen. Crossing over by Bald Butte, a hill of trachyte, we reached the road again. The excursion was not altogether a satisfactory one, though showing the presence of the limestone at this point, but, as an investigation into the further structure of the hills, it was not successful. The difficulty lies in the fact that the hills are principally of igneous origin, and the thrusting in of the trachyte between the sedimentary rocks has destroyed the regular succession in the strata TO YELLOWSTONE NATIONAL PARK. 109 which would otherwise exist. Further than this, while the trachytic hills are mostly bare and rocky, the other hills are, with the exception of the occasional sharp ridges of limestone, covered with grass and timber, so that little can be seen by one who must hurry on and make few stops. Probably two-thirds of the area of the hills is covered with trachyte, of which that found at Cone Butte may be taken as the type. CAMP LEWIS TO THE JUDITH GAP. From Camp Lewis, the road passes on thirty miles to the Judith Gap, crossing a portion of the country which has some promise of becoming valuable in time. Quite a number of running streams pass through it, of which Cottonwood Creek, Little Trout Creek, and Buffalo Creek are the most important. The latter becomes dry late in the season. Little Trout Creek is famous for the num- ber and beauty of the trout which it contains. In the immediate vicinity of the streams, the grass is excellent; but, on the higher prairie, it is rather thin. The streams flow fresh and cold from the neighboring Snow Mountains, and could doubtless be used extensively in irrigation. This Judith Basin is a region that has been highly spoken of, and it will no doubt in time furnish farms for hundreds of settlers. Very little opportunity for geological work is afforded over this portion of the route; for the prairie is much of it almost level, sloping away to the northwest to the Judith River, and giving no exposures of the underlying rocks. Considerable surface-drift is found here, which is entirely local, consisting, for the most part, of pebbles and masses of a blue limestone, some of them con- taining Carboniferous fossils. The source of this limestone is to be found in the Snow Mountains, whcib rise ten or twelve miles to the east, and from which it has been very abundantly carried off. A short distance before reaching Ross’s Fork, a bluff was examined, ofa black shale, containing many reddish iron concretions, but no fossils; and a little farther on, to the left of the road, were seen some washed exposures of light-gray shales, also without fossils. Not far beyond, the soil becomes red again; and, for a distance of several miles up to the Judith Gap, the presence of beds of red clay is indicated. Associated with them was a limestone, impure and knotty, with many veins of calcite. These red-clay beds appear also at the foot of the Snow Mountains, and, as has been said, also at the foot-slopes of the western end of the Judith Mountains. Their thickness seems to be small. They appear to belong to the Cretaceous, which doubtless extends under the grassy prairie from Camp Lewis to the Judith Gap. SNOW MOUNTAINS. From Buffalo Creek, ten miles before reaching the Judith Gap (that is, north of it), we made a short detour, to examine the west end of the Snow Mountains. This range extends in an approxi- mately east and west direction for a distance of some twenty miles. It is low, like all the other minor ranges. The average height can hardly be more than 2,000 feet above the surrounding prairie. Buffalo Creek takes its rise in the north side of the west end of the range. Following up the stream for a mile and a half from where the road crosses it, we found some outerops of sand- stone, with indistinct vegetable remains, undoubtedly Upper Cretaceous. A little farther—this on the north side—on the hill-tops, there was a gray sandstone, and below it, on the hill-side, a sand- stone of a deep yellow color. Both of these broke into irregular, wavy fragments. Dip 10° west- erly; strike north 20° east. These, which are in thickness perhaps 60 feet, are probably Upper Cretaceous. On the opposite (south) side of the stream appears a thinly-laminated sandstone, with a south- westerly dip of 10°, but a strike north 30° west. Beneath this followed the slopes of red soil, pointing to the presence of thin beds of clay beneath, like those at Camp Lewis. Following and underlying this was a firm, thick sandstone, breaking into massive slabs, which covered the top and sides of the hill, giving it much the appearance of having been paved; the strike was as before. Beyond, also south of the creek, a hard, gritty sandstone was noticed, with layers containing a large number of poorly-preserved shells. These were not specifically recognizable, but have been iden- tified as Cretaceous by Mr. Whitfield. Beneath this was what seemed to be a second deposit of the red-clay beds. These last are visible, though not so distinctly, on the opposite side of the creek, FIO RECONNAISSANCE FROM CARROLL, MONTANA, where they are followed by about 5 feet of a firm limestone, and that by a considerable thickness of green and black shales, which last may be traced for a short distance on both sides of the stream. It is to be noticed that the strike and hence the dip of similar layers on both sides of the stream is quite different; and, though further study is needed to make out all the facts, we think it can hardly be doubted that at this western end of the mountains there is a distinct fold; the axis probably running a little north of west. Continuing up to the source of the stream, we found the limestone here with a very slight dip to the northwest; strike northeast. The final point which we reached was a little caiion, with high and bold limestone walls, from which we obtained a few not very perfect Carboniferous fossils, viz: 1. Zaphrentis centralis (2), Ev. & Shum. 2. Streptorhynchus Keokuk, H. 3. Spirifera centronata, Winch. 4. Stictopora, sp. To reach these Carboniferous rocks, we had doubtless passed over in succession the Cretaceous rocks, having perhaps a thickness of 900 feet, and also the Jurassic, if it exists here. We found no fossils belonging to this age, and doubt the existence of any considerable thickness of Jurassic beds. The limestone with the green and black shales noted above may possibly belong here. Leaving the ridge, we turned at right angles to it; that is, nearly north. Here we passed over, first, the limestone dipping northwest, then successive beds of sandstone with beds of red clay inter- stratified. Near the foot of the hill, a reversal of the dip occurs in the sandstones, pointing toa minor fold parallel to the general course of the range. No older rocks than the Carboniferous lime- stone were observed ; and from the numerous limestone pebbles containing Carboniferous fossils, picked up at different points along the sides of the mountains, it is safe to conclude that the range, as a whole, is made up of Carboniferous limestone; the younger rocks lying on its outer slopes. No evidence of any older rocks than the Carboniferous was noted ; certainly not of any crystalline rocks. The trachyte, so common in the neighboring Judith Mountains, seems to be almost or entirely absent, LITTLE BELT MOUNTAINS. The Judith Gap is the divide between the Judith and the Musselshell Rivers. At this point the Little Belt Mountains and the Snow Mountains approach one another quite closely. The former are quite an extended and somewhat irregular range, reaching for a long distance north and west. Of its general geology, we can say little, as we can speak only of a few widely-separated points where we were able to visit it. One of these points was the extremity of the range at the Judith Gap. Near the Gap, we have already spoken of finding, on the north side, beds of red clay, which are associated with a little limestone, and nearer the hills with an underlying sandstone. Crossing the hills, which form the extreme eastern end of the range, perhaps a mile west of the Gap, we found a bed of yellow sandstone, which contained Ostrea congesta, Con.; then, some distance up the slope, a limestone containing corals, and dipping in a northerly direction; then some thin layers of limestone containing Productus. The fossils found here were as follows; the identification by Mr. Whitfield: . Ostrea congesta, Con. . Cyathophylloid coral. . Campophyllum torquium, Owen ??. . Spirifera centronata, Winch. . Spirifera, sp. May possibly be Spiri/erina Wentuckensis. . Productus, sp. Resembles P. Wortheni, I.; but perhaps more nearly related to P. multi- striata, Meek. 7. Schizodus, sp. Nearly or quite 8. Rossicus, (DeVern.,) M. & W. Here were seen. 20 feet of green and black shales, dipping 50° northeast. From here, as we go up and across the hills, the strike gradually changes, and with it the dip, so that on the south side of the hill we have strata dipping southeast instead of northeast. ‘The succession observed here is ‘from below up: Limestone, dip 65° south, strike north 70° east..............cceeee econ sees 2 feet. Red clays, with purple slates underlying it.....2.. 20... eee eee eee eee 10 feet. ee Ct He O Lo j=) TO YELLOWSTONE NATIONAL PARK. V1 These beds bend around some 50°, so that in a vertical section they describe a quarter circle. The upper and central part of the hill consists of limestone, overlaid by a considerable thick- ness of slates and sandstones, dipping mostly east-southeast. The hill alluded to forms the extremity of this portion of the Little Belt Mountains. Farther along to the west, in the main range, is a limestone which has every appearance of dipping under all the rocks thus far men- tioned ; it probably corresponds to the firm limestone which forms the lower portion of the Carbon- iferous as developed in this region. The structure of this hill, thus imperfectly made out (a hasty run across it while the party was going round being all that circumstances admitted of), may be better understood upon the statement that it is an anticlinal fold; the axis pointing about north 30° west, and somewhat elevated in this direction. The south side of the fold is apparently the steeper. JUDITH GAP TO THE MUSSELSHELL CANON. From the Judith Gap to the Musselshell Cafion, a distance of rather more than forty miles, the underlying rock belongs for the most part to the Upper Cretaceous; the only fossils found hav- ing been referred by Mr. Whitfield, as stated below, to No.5. his district is remarkable, perhaps more so than any other seen by us, for the deep and wide valleys which have been cut through the nearly horizontal rocks, and which lead away from the neighboring range, the Little Belt Mount- ains. There are now no streams running from the mountains, with the exception of Haymaker’s Creek near the Forks of the Musselshell, and yet the otherwise remarkably level prairie is broken by a number of striking ravines or valleys. These are all alike in that they show no evidence of any important action by recent running water, but, on the contrary, point to agencies which must have done their work in glacial times. The beds of these valleys, and also, though to a less extent, the prairie above them, are strewn with pebbles and masses of limestone, whose source is in the monntsing, only a few miles distant. Three very conspicuous valleys, one of them a mile wide, with ‘steep banks more than one hundred feet in height, are crossed before going twelve miles from the gap. Hopley’s Hole is by far the most remarkable of these. A section is given in the following cut (fig. 8). \ Fig. 8. Sandstone. ines. eT A Section across Hopley's Hole. The width of the coulée at the top is about 1,000 yards. From the level of the prairie on either side, there i is a steep plunge down; the total depth to the dry bed of the little stream being, according to aneroid measurements, 150 feet. On the west side, a second terrace of 50 feet in height is very distinct, while on the eastern slope a similar terrace, at about the same height, seems to be indicated ; at present, however, there remains only a series of little conical hills all lying in a continuous fine and presenting quite a peculiar appearance. This ravine is now dry, with the exception of a few springs of moderately good water on the west side. The water from these springs moistens the ground for a little distance about the point where they appear, but soon sinks out of sight. In the early part of the year, after the melting of the snow, more or less water evidently runs in the bed of the stream, which is dry in summer; but its erosive power is small, and there is nothing in the present relations which will explain the existence of such an extended valley. Hopley’s Hole is important to those who pass over this road, not only as furnishing one of the few sources of water in this part of the route, but also because along the eastern edge of the valley there is here and there a little timber ; a few straggling pine-trees which have ventured out into the prairie from the adjoin- ing hills, and which show, by their appearance, that they have here a hard struggle for existence. The western slopes of this ravine, over which the limestone pebbles before mentioned are thickly scattered, are more gradual than the eastern; and, while the former are covered with thin grass, the latter shows a line of exposure of the sandstone which underlies the level prairie here. The upper 112 RECONNAISSANCE FROM CARROLL, MONTANA, part of this is yellow and quite ferruginous; that below whitish and a little shaly. It varies some- what at different points; in one place turning into a soft, dark-colored slate in very thin layers. The whole exposure may be 15 or 20 feet in thickness; the sandstone having a very slight south- easterly dip. No fossils could be found, and the rock seemed to be without any special character- istic features, with the exception of pipe-stem pieces of carbonate of lime, which were quite common. They occupied a vertical position, sometimes curving more or less, and were 6 to 15 inches in length; possibly they were holes in the sand made by borers and subsequently filled up. West of Hopley’s Hole, the plain is nearly level for a long distance, broken only by one or two gullies. The general slope of the whole is very gradual to the south toward the Musselshell River and far beyond. In this direction, there is nothing to break the view, and the eye wanders unre- lieved over a vast range of dry, parched prairie, from which, at midday, the heated vapors arise, producing the illusive phenomena of the mirage. Haymaker’s Creek, twenty-five miles from the gap, offers another example of the extensive erosion which has taken place in this region. The stream at present carries very little water, and that quite strongly alkaline, especially late in the summer, at which time it barely moves at all. On the west side, the terrace is high and distinctly marked. It may be traced from the mountains to the Musselshell River with the same gradual slope noticed elsewhere; here also quite inde- pendent of the dip of the strata, which make a small angle with its upper surface. On the east side, the slope is very gradual; the final height not being attained for several miles. A short distance below the road-crossing, the sandstone is exposed. For the most part, it is a fine-grained rock of even texture, and of a light-bluish color, becoming yellow on exposure to the weather. Much of this lies in exceedingly thin, paper-like layers. There are also a few layers of a blue, impure limestone, and toward the top a bed of coarse sandstone, almost a conglomerate, containing some indistinct plant-remains, shells, and a few sharks’ teeth and vertebra, which show the beds to be Cretaceous No.5. The remains are too poorly preserved to be specifically identified. The genera are as follows: 1. Grypheea, sp. 2. Ostrea, sp. 3. Lamna, sp. (teeth). 4, Galeocerdo, sp. (teeth). The strata have a slight dip (5°) northerly; and a little to the north, where the thin-bedded sandstone only is visible, the beds are horizontal or dip slightly to the south. A mile or two far- ther, «4. ¢., west, we meet several outcrops of a dark ocher-yellow sandstone, in which some pipe- stem calcareous fragments suggested those found at Hopley’s Hole. A few indistinct vegetable remains were also obtained, but nothing characteristic. The slight dip is reversed in a subsequent exposure, showing an extremely low fold, the meaning of which will be explained later. Fol- lowing these are a series of bluffs, sandstones, or sandy shales, some of which we were enabled to visit. None of them afforded us any fossils. Over these, we noticed a few washed exposures of white and cream-colored clays. These doubtless all belong to the Upper Cretaceous, though, in view of their very slight dip, it would require more time than we had at our disposal to make out their exact stratigraphical rela- tions. In general, it may be said of these sandstone bluffs that they are more tilted as we approach the mountains, and seem to owe their position to the forces which threw up this range of hills. On reaching the Forks of the Musselshell, we come into a more attractive region. From the Judith Gap to this point, the prairie is almost a desert, dry and parched, and the grass very thin- Both branches of the Musselshell River, however, are fine running streams, and at their union the aliuvial country is wide and susceptible of profitable cultivation. Just before reaching the Forks, we passed a ranch where a system of irrigation had produced excellent agricultural results. From the Forks our road took us along the north branch of the Musselshell River, and two miles beyond we entered the Musselshell Cation. The open country here is rough, and is charac- terized by many step-like ridges of sandstone, on one side steep, showing the edges of the strata, and on the other sloping off gradually, and covered over with grass. TO YELLOWSTONE NATIONAL PARK. 113 MUSSELSHELL CANON TO CAMP BAKER. The Musselshell Cajion divides the Little Belt Mountains from what is called the Elk Range. It is a narrow mountain-ravine, with steep hills on both sides, which sometimes approach very closely together, and again recede, giving room for a little strip of green meadow-land on the border of the stream. It is, throughout its length of eight miles, very picturesque, especially near the eastern end, where the abrupt walls and buttresses of white limestone contrast strongly with the dark-green foliage of the pines and spruces. All together, it was a most delightful relief from the parched alkaline prairie on which we had made our camps for the preceding fortnight. The waters of the stream are clear and cold, and abound in what is apparently a species of Coregonus. This fish rose readily to a fly, affording to some members of the party fair sport, and furnishing a very agreeable variety to the sameness of our daily fare. On leaving the open country and entering the cafion, we came abruptly upon the Carboniferous rocks. A band of red clay a few feet wide is quite conspicuous at its eastern opening, followed by several others less striking and quite narrow, all red or ocher-yellow. These are interstratified with a sandstone which contains great numbers of Ostrea congesta, Con., as identified by Mr. Whit- field. These dip west 50°. Immediately following these are successive layers of limestones and slates, and then several hundred feet of limestone. From the former beds the following fossils were obtained: 1. Bryozoan (undescribed). . Aulopora, or bases of Syringopora. . Zaphrentis centralis, Ev. & Shum. Productus semireticulatus, Mart. Productus muricatus, N. & P. Productus, sp., probably young of P. punctatus. . Productus, sp., approaches forms referred to P. Prattenanus. . Productus multistriatus, Meek. . Athyris, sp. 10. Pinna Ludlovi, Whitfield (n. sp.). The overlying limestone-beds all dip like the others, a little south of west, 50° to 60°. These limestones form a number of high vertical walls and isolated towers, which are worn out into a variety of fantastic forms which have already been alluded to. These are especially conspicuous on the north side of the stream, though similar walls are seen too on the other side in the line of the strike. This limestone is very cherty, the fragments of flint being numerous; and it is to their presence that the rock owes the peculiar forms in which it now appears. The walls show no evi- dence of structure or stratification. They abound in little cavities and holes, often partially filled with stalactitic masses of carbonate of lime, showing the extent to which the solvent action of water has worked upon them. A similar relation of the rocks was observed on the upper slopes of the Bridger Mountains ; that is, the series of bright-red indurated clays, with a little Cretaceous sandstone, followed by thin layers of limestone full of Carboniferous fossils, and then 500 feet or more of a firm cherty limestone, weathering out into walls showing no stratification and rarely containing fossils. The limestones are overlaid by (Jurassic and) Cretaceous and underlaid by Silurian. The similarity in the succession of the beds makes it quite certain that the underlying rocks at the entrance of the Musselshell Cafion are really the youngest, forming the upper part of the Carboniferous series, while the rocks which follow and overlie, apparently conformably, are older, and, in part at least, Lower Silurian. The later layers of the limestone, going west through the caiion, have a somewhat different look from those seen farther to the east, being darker-colored and more uniform in appearance. Leaving the limestone, we passed over perhaps a quarter of a mile without finding any rock in place, though on the hill-slopes to the south masses of a hard, reddish quartzite indicate the pres- ence of this as a member of the series. The next exposure reached was an argillitic slate, with veins of quartz, also dipping westerly. The hills for a considerable distance are rounded and covered with grass, exposing no rocks within the limits that we were able to cover. The prevailing rock, as we continue up the caiion, following the course of this branch of the 15 w ONIA TH ww i=) 114 RECONNAISSANCE FROM CARROLL, MONTANA, Musselshell, is a clay-slate, of which there must be a very great thickness, interstratified with some sandstone-beds. The central portion of the range is trachyte, which is very abundant, forming a series of high hills and seriously interrupting our observations in the succession of the strata. Occasional outcrops of sedimentary rocks, principally slates and shales, appear; but as they contained no fossils, and as their succession was everywhere interrupted by the trachyte, their relations to what had preceded remain very uncertain. On the whole, the caiion gives a very fair exposure of the successive rocks, and to one who could do more than take passing notes in riding through it would no doubt yield some important facts. Leaving the cajion, we emerge into an open rolling country, covered with grass, and with few exposures of the underlying rock. This, as far as could be observed, was a yellowish fragmentary slate, with occasional veins of quartz and calcite. A number of openings have been made by indi- viduals prospecting for metal, but only faint indications of copper were observed. At Copper- opolis, a mine has been sunk some 40 feet into this slate, and some very fair copper-ore and a little silver ore are being taken out. The mine is being worked on a very small scale indeed, only two men being engaged in it; but the ore obtained is sufficiently valuable to pay its way to the Hast, where (at Baltimore) it is smelted. Near this point we pass the divide, and descend rapidly to the valley of Deep Creek, leaving the Musselshell behind us, and striking waters that flow into the Missouri near Sun River; that is above Fort Benton. The valley of Deep Creek, though here somewhat narrow, becomes rapidly wider as we follow it down to Camp Baker. It is a fertile alluvial plain, and is no doubt susceptible of successful and profitable cultivation. There is as yet, however, no market for cereals in the vicinity, and the grassy meadows are given up to large herds of cattle, which range at will over the valleys and foot-hills. Every settler owns some cattle and horses, and these require little or no care, even in winter. The inhabitants state that they cut no hay for the winter-consumption of their stock, nor do they build stables or shelters for them at that season. The animals are said to run out all winter and to keep fat on the standing hay. Montana beef has quite a reputation for excellence west of the Missouri, so that the raising of cattle is likely to prove the most profitable pursuit for the settler until railroads shall have supplied him with a market for other products. Deep Creek, like most of the streams in this neighborhood, abounds in delicious troutand grayling (Thymatlus), both of which attain a large size, sometimes weighing three pounds and more. To our left, as we come down the valley of Deep Creek, we have the Elk Range high above us, the summits of which consist of trachyte. This has taken many curious forms, as pinnacles and towers, which rise above the timber, and give to the hills a very castellated appearance. An out- crop of purplish-red slate to the left of the road, and dipping 40° southerly, deserves to be men- tioned, as its exact counterpart was seen at Camp Baker, sixteen miles distant, there overlying the Potsdam limestones. To the right, that is west, were a series of limestone ridges with masses of trachyte interstratified. These beds of trachyte have all the appearance of sedimentary rocks at a distance, so entirely do they conform to the uptilted beds of limestone. These latter have a dip of 40° to the southwest. They have the appearance of the Potsdam limestone beds just spoken of as occurring at Camp Baker, and since, if continuing, their strike would make them appear there, it is hardly to be doubted that they too are Silurian. The Sulphur Springs are about 17 miles from Copperopolis, and lie at the point where the road to Camp Baker turns at a sharp angle to the west. The springs have a temperature of 150° or thereabouts, and are strongly impregnated with sulphureted hydrogen. They are quite well known through the Territory, and are believed to have the beneficial effects generally ascribed to similar springs, and to be especially valuable in cases of rheumatism, a complaint very common among miners. Considering the vast trachytie upheaval which has taken place in that vicinity, the pres- ence of hot sulphur springs can hardly excite surprise. From the Sulphur Springs, the road continues west, at the foot of the Big Belt Mountains, cross- ing a wide grassy plain, which has an even, uniform slope up to the edges of the hills. The stream, some ten miles from the springs, where Newland Creek joins it, runs through a gorge of por- phyritic trachyte with a distinct columnar structure. This rock borders the creek for some dis- tance, and the dike runs across the road, continuing on in a northerly direction. From here a TO YELLOWSTONE NATIONAL PARK. Lie march of seven miles took us to Camp Baker; the road passing along by bluffs of Miocene Tertiary, to be described later. CAMP BAKER. At Camp Baker, where we made a short stay, we were the recipients of most kind hospitalities from the officer at that time in command there, from whom also we received valuable informa- tion in regard to the surrounding country. During the time spent at this point, we were enabled to make an imperfect reconnaissance of the immediate vicinity. The descriptions given below may be better understood by reference to the following cut (fig. 9): Fig. 9. i Miocene, Pea) (eee (Fellow slates.) Miocene. Camp Baker lies in a broad plain, which is surrounded on all sides by mountains, of which the Big Belt to the south are the most conspicuous and highest. We are here on the eastern border of the mountain-region, which extends far to the westward. The valleys of Deep Creek and its tributaries are filled with deposits of Miocene Tertiary. These consist for the most part of homo- geneous cream-colored clays, so hard as to be with difficulty cut with a knife. The lower layers are generally more loose and homogeneous, while the upper beds are harder, firmer, and sometimes quite calcareous. Some of the upper beds are remarkable for the large number of white clay con. cretions which are found in them. The beds are horizontal, and rest unconformably on the somewhat upturned yellow and red slates below; the clays of which they are formed resemble closely those of the Miocene beds at Scott’s Bluffs near the North Platte River in Wyoming. The deposits at Camp Baker have been extensively denuded, and nowhere reach any very great thickness. At a point about three miles southeast of the post, some bluffs were noticed where the Miocene beds attained a thickness of 200 feet, and these were capped by 50 feet of Pliocene clays, both beds containing characteristic fossils. We saw the first exposures of these beds a few miles west of the Sulphur Springs, just after crossing the high ridge of trachyte before referred to, through which Deep Creek flows. From here, the lake bed was traced continuously along Deep Creek for a distance of fifteen miles. Beds of the same character, containing fossils, were found on Spring Creek to the east, on White-tailed Deer Creek, about seven miles to the north of Camp Baker, as well as on Camas Creek to the south- west. On Camas Creek, the beds are exposed for a mile or more in bluffs ranging from 20 to 25 feet in height. The exposures on White-tailed Deer Creek are much more extensive than those last 116 RECONNAISSANCE FROM CARROLL, MONTANA, mentioned. Those on Camas Creek are in thick, rather indistinct, layers, and contain more or less bluish sand in irregular layers, and sometimes a little coarse gravel. Traces of this deposit, containing what appear to be remains of Rhinoceros, were also observed two miles or more south of Moss Agate Springs (to be referred to later), and at a considerable elevation above the creek-bed. With more time than we had at command, they could, no doubt, have been traced much farther, although in many places the beds have been washed out, or have been covered by the later local drift. Tn the Miocene beds were found a species of Rhinoceros; several species of Oreodon, Leidy, and Eporeodon, Marsh; a canine tooth apparently of Hlotherium, Pomel; and remains of Turtles. In the Pliocene beds, the principal fossils were a species apparently of Merychyus, Leidy; remains of an equine smaller than the modern horse; and Pliocene Turtles. These fossils have not yet been carefully studied, and, for this reason, their relation to the remains found in the other lake-basins of similar age cannot here be stated. The line of separation between the Miocene and Pliocene beds is, in some places, well marked. It consists of about six feet of bard sands interstratified with layers of very small, water-worn pebbles, soldered together into a hard mass. Each of these layers is about 6 inches in thickness. Immediately above these strata, the Pliocene fossils were found. It is known that in the neighborhood of Fort Shaw, and near Helena, Pliocene deposits exist; and near Fort Ellis, and in the valley of the Yellowstone, we saw, but were unable to examine, gray sands and marls, which Dr. Hayden refers to the same age. No Miocene beds, however, have been identified at any of these localities. It seems probable that, in Pliocene time at least, the Baker Lake may have extended north to the Missouri River, and perhaps up that stream to the “Three Forks”, thus connecting with the lake which existed near Fort Ellis. Indeed, it would seem that we just touched upon the southern edge of this basin, which may have extended far to the north and west. An interesting point in connection with these deposits is the fact that, with the exception of one deposit in Colorado, they are at a much greater elevation than any other beds of the same age now known on the continent. The elevation of the White River beds is about 3,000 feet, and that of the Oregon basin somewhat less; while that of the deposits near Camp Baker is over 5,000 feet. On the east side of the plain on which Camp Baker stands, the Miocene has entirely disap- peared. It is to be noticed that these Tertiary beds were deposited after the elevation of the older rocks, and that most of the denudation now visible in these rocks must have been accomplished before the deposit of the Tertiary, as it is repeatedly seen filling the depressions and unevennesses in the slates, as also covering over the ridges of trachyte. Underlying the Tertiary, and tilted up at a small angle, appear a series of yellow slates and shales, which are quite generally distrib- uted in this region, though not seen elsewhere. They are seen geverally as a fine-grained slaty rock, friable and weathering readily, so that exposures of the rock in place are rarely found. Ovca- sionally, there are observed in them immense black concretions of remarkable structure. In the interior, these consist mostly of a calcareous clay, very hard, and showing distinctly what is called the cone-in-cone structure. Outside of this, the lime is purer, though lying in concentric layers, and the exterior shell is made up of fibrous calcite half an inch in thickness. The clay cones radiate from the center of the concretions. The slates are destitute of fossils, and their age is only a matter for conjecture. The most remarkable feature connected with them is that they have, in spots, a bright brick-red color; thus, in riding over the country, a patch of intensely red-colored soil will be seen here and there, strongly suggestive of the burned lignite beds of the Missouri River. The slate has at such points the appearance of burned pottery; the material being harder and firmer than the surrounding rock. In some cases the red color was uniform in the rock; but generally it was distributed in successive bands, as though produced by the action of hot water. The red patches are quite local, and seldom cover more than a few square yards, though in one case they were seen extending along a range of hills for a hundred yards or more. That the effect produced has been caused by the action of heat cannot be questioned, though under what conditions no attempt is made to conjecture. As has been said, these shales and slates are tilted up unquestionably ; but their exact relations to the underlying rocks could not be made out without more opportunity for investigation than we had, * TO YELLOWSTONE NATIONAL PARK. 117 The difficulty in settling the matter arose from the fact that the loose shale seldom showed its true position. We find this formation in the immediate vicinity of Camp Baker, both to the east, where it forms high hills 250 feet above the plain, also to the south and west, where it is intersected by some dikes of porphyry, and quite extensively below in the valley of Deep Creek, as well as along the valley of White-tailed Deer Creek. Its general distribution seems to conform to a certain extent to that of the Miocene Tertiary that is filling the valleys between the older rocks. The older rocks alluded to form the ranges of hills conspicuous about Camp Baker. Immedi- ately north of the post lies a range of hills, having an east and west trend, through which Deep River takes its course by means of a cation, which gives an excellent section of the rocks of which the hills are composed. The rocks all dip south, and this dip continues the same for a mile or two to the north. South of the range alluded to, and close to the post, are several minor hills, and, at a distance, a series of others all singularly alike in appearance. The section of rocks alluded to is as follows: Ss QOALtZILC eink! eka oe evan deen eee Sand ves lee eas Bees we ee te see ee 20 feet. A series of colored shales, chiefly red, but also green and blue, with a bed of ‘trachyte interstratified «. 2... veaies ec cesses ere ees ceie eee e wwe 150 feet. Two ridges of limestone, in all........... ee 80 feet. These limestones show abrupt bluffs to the north, and dip southerly. In the northernmost of the ridges were found— 1. Crepicephalus (Loganellus) montanensis, Whitf. (n. sp.) ; 2. Obolella, sp.? ; identifying the formation as Potsdam, according to Mr. Whitfield. Following this is a quartzite, which forms the south side of the hill alluded to. The section is continued through the cafion : quartzite 40 feet, firm and solid, with areddish tinge of color, breaking into massive blocks; under- neath is a series of bright green slates, followed by a variety of clay-slates, mostly dark-colored, with occasional beds of hard solid quartzite and some thin layers of limestone. After half a mile, the ridge is passed, and the stream comes out into the open country. The rocks, for a mile or two, however, are mostly the same in dip, and are conformable. They are chiefly dark blue shales. The appearance of the quartzite hills in this neighborhood is peculiar, as they all have a grad- ual slope to the south, but are nearly vertical toward the north, on which side there is at their foot a talus of large cubical blocks of quartzite. We were unfortunately not able to visit the Big Belt Mountains. CAMP BAKER TO FORT ELLIS. From Camp Baker, the party marched to Fort Ellis; the road for a short distance being the same as that before traveled. The road passes to the right of the Elk Range. Twenty miles from Camp Baker, we reached the extremity of this range. At this point, we passed immediately from the grassy meadow onto the older rocks. Here we found first a red shale similar to that at Camp Baker, and also to that observed higher up, four miles the other side of the Springs. This was fol- lowed by a heavy massive quartzite, a little reddish and very firm; and overlying this was a considerable thickness of limestone. This last is well exposed just above Moss Agate Springs, and in some of the layers we found an abundance of fragments of Trilobites. The limestone is much of it very cherty, and in many places it formed the same abrupt and peculiar shapes noticed elsewhere, Just above Moss Agate, there is a little superficial synclinal fold in the limestone, the axis of which has an approximately northeasterly direction. Moss Agate Springs takes its name from the frag- ments of flint, chalcedony, and agate, which are common on the adjoining hills, and many of which, from the presence of the arborescent forms of psilomelane, are popularly called ‘‘moss agates”. These fragments of silica are evidently from the limestene, and are quite characteristic of it. Similar fragments of chalcedony, though without the moss effect, were found abundantly in some of the little hills just by Camp Baker. The limestone is evidently the same as that, as is moreover proved by its association with the quartzite and by the few fossils found in it; these were all of one apecies, a new Trilobite,—Arionellus tripunctatus, Whitf. (n. sp.). 118 RECONNAISSANCE FROM CARROLL, MONTANA, The road from Moss Agate passes, it is true, more or less at the end of the bills, but at such a distance from them as to afford but little opportunity for observation. From a distance, it is observed to how great an extent the hills are made up of limestone, with the conspicuous trachylic prominences before mentioned. From the limestone, we pass immediately to a dark, somber sand, stone of granular texture and quite peculiar in appearance. This had a dip to the west, and con- tained some indistinct plant-remains. On our return journey, we found time to touch at the southeastern extremity of the same hills near the source of Flathead Creek, and here we passed directly from sandstones resembling the one spoken of to the limestone exactly similar to those so often observed at various points in this range. It agreed in all respects with the other exposures. A few indistinct fossils were obtained from a loose block, which had evidently come from close at hand, and these show it to be Carbon- iferous. They were identified by Mr. Whitfield as Spirifera centronata, Winch. The country near the branch of Deep Creek on the south side of the Elk Range is attractive and covered with good grass, supporting large herds of cattle; but, after passing the low divide which separates the above-named streain, a tributary of the Missouri, from Shields River, a branch of the Yellowstone, a more or less decided change is observed. The prairie is here dry and barren, espe- cially to the south of Cottonwood Creek, and supports nothing but a thick growth of sage-brush. It is watered by several running streams beyond Sixteen-mile Creek, of which Cottonwood is one of the most important, in view of the fact that its banks are fringed with fine trees, from which it takes its name. As we approach Bridger’s Pass, the character of the country improves again, and the large numbers of cattle met with near this point indicate its capabilities in the way of grazing. Of the geological relations of this part of the road, we saw little on our way south. While returning, how- ever, our opportunities for observation were better, and the results are presented immediately below. Bridger Pass is a high mountain-divide, thickly wooded, and with the high limestone cliffs of the Bridger Mountains overhanging it on the west side. The scenery is fine, and the change from the bare prairie to the grateful shade of the wooded mountain-side is gladly weleomed by the traveler Geologically speaking, the prevailing rock is the dark sandstone described later, and known to belong to the Upper Cretaceous. The position of the strata is nearly vertical. An occasional dike of igneous rock was observed, and one of these was conspicuous on the north side of the pass. It consists of a greenish basalt in spherical nodules, separating in the fracture into successive thin slabs. High above the road,as we approach Fort Ellis, we noticed the horizontal strata of the Pliocene Tertiary, which, according to Hayden, extends far away toward the west.’ From Fort Ellis, the party extended their trip into the Yellowstone Park. We introduce here, however, the additional observations made on our return-trip through the country just mentioned. BRIDGER MOUNTAINS. On our return to Carroll from Fort Ellis, early in September, we encountered much trouble at first from the condition of the roads, which were almost impassable, owing to the unprecedented amouut of rain that the country had recently received. We made use of the delay which this occa- sioned in the movements of the wagons, to make a little exploration of‘ the Bridger Mountains, or East Gallatin Range, as it is sometimes called. These observations could not be extended beyond the east side of the range, and hence are only fragmentary. Considerable time was devoted to the same mountains by Dr. Hayden and his parties in 1871 and 1872, and reference may be made to his reports for those years for the facts observed by them. This range of mountains is especially conspicuous as viewed from the east side, rising up steeply from the deep and narrow valley, and terminating in a nearly perpendicular white wall, with a sharp knife-edge for its summit. We ascended the ridge from two points: first, September 4, from a point in the valley below, about six miles from Fort Ellis; and, again, September 5, from our camp, a short distance to the north side of the divide in the Bridger Pass. The rock of the valley, and indeed of the pass, as far as observed, is a sandstone of somber tints, gray, brownish, or greenish. The texture is generally granular and gritty, and the rock is more or less speckled with grains of quartz and feldspar. In general, it may be said to be a sand- TO YELLOWSTONE NATIONAL PARK. Lie stone ma from poorly-assorted materials. It contains, in some layers, impressions, generally indistinct, of vegetable remains. It is referred, as a whole, to the “Coal Series”, by Dr. Hayden ; and he further estimates its thickness at 10,000 feet. This seems to us considerably to exceed the truth. We found the same series of sandstones extending in anumber of wide folds over the prairie to the north; and this would make it probable that even if there be a thickness of 10,000 feet of vertical strata belonging here, it has been formed by the pressing together of an anticlinal fold par- allel to the range of mountains. This is the more likely, as the strata of the beds all dip steeply, and are often overturned, the dip being reversed. Ascending the hills from the point first mentioned, somewhat north of the Bridger Peak, we passed for a long distance through the timber, crossing, here and there, little open parks and valleys, up to the foot of the range proper. Up to this point, we had seen but few exposures of rock, and those similar to the sandstone already described. The section observed from this point to the summit is as follows: Red earth and clay, with occasional masses of indurated red clay, seldom showing any stratification ; in all, 60 feet. Following this, and, in its present position, overlying, though, in fact, geologically, underlying it, is a thick-bedded sandstone, dipping 60° west; strike north 20° west. This rock was mostly yellow and ferruginous; its texture gritty, at times becom- ing a mass of coarse pebbles. Occasional layers were calcareous, and contained multitudes of indis- tinct Cretaceous shells (see list below). These often yielded to the weather, the rock becoming then rusty and cellular. The visible thickness of this deposit was 40 feet. Then, after a small interval, follows a firm, blue, compact limestone; the first layers containing a few Jurassic fossils, and those following the same in greater numbers (see list below). The thickness of this bed is about 60 feet. Jfollowing this is a sandy limestone; and then comes the Carboniferous limestone, which forms the remainder of the upper part of the hill for a distance of 700 or 800 feet, the total thickness of these strata being perhaps 500 feet. This limestone has the same massive and, on weathering, structureless character remarked elsewhere. Some layers seem to be a conglomerate of fragments cemented together by a calcareous paste. Thin layers of dark flint, two or more inches in thickness, are common, running irregularly through the limestone blocks, and also isolated masses of the same rock of greater or less size. At thesummit, the dip is 70° east. Fossils were not com- mon in this rock; those found were chiefly corals. Continuing along the narrow summit for some distance toward the north, all the time on the solid limestone, we found its dip varying consider- ably from east to west. On descending, a band of red clay was passed over at the foot of the com- pact limestone, and calcareous layers interstratified with it contained some Carboniferous fossils. The dip here was west. This is the same band noted on the succeeding day, and to be described farther on. In other respects, the return trip added nothing to what had been before observed. On the following day, the ridge was ascended again from a point some eight miles beyond; but it did not yield us the complete section of the rocks that we had hoped for. The approach to the mountains was, for the most part, of necessity through the timber; the rock appearing but seldom, and this the dark-colored sandstone before noted. What was observed here would not enable us to do more than guess at its total thickness. Emerging into the open ground, high up on the range, we came upon a high ledge of a very massive, coarse sandstone, or rather a conglom- erate. The strike was north and south, and the dip east 35°. The thickness actually exposed was small. Rising 500 feet from here, we found a series of limestone exposures mostly covered with grass. — They yielded some Jurassic fossils, similar to those obtained the day before. The rock following was, as before, a white, sandy limestone, sparkling in the sun, and without fossils; then appeared the Carboniferous limestones. The point we had now reached is conspicuous from all parts of the surrounding country, being marked by two lines of deep red, like bloody gashes, in the side of the mountain. These red bands, though narrow, may be traced along the east slope of the hills for a considerable distance north and south, and form quite a striking feature of the range. The lower bed, made up of an indurated red clay, was only 4 feet in thickness ; but the color was very intense. Tutersteatified with these bands was a small thickness of variegated limestone, generally purplish, sometimes vermilion or greenish. This limestone abounded in Carboniferous fossils; not infrequently the shells occupied the center of little‘grayish circles in the reddish rock. These soft red bands have generally yielded 120 RECONNAISSANCE FROM CARROLL, MONTANA, to denuding influences, and the point where we stood was a narrow neck of land with a deep gulf opening below us to the south and southeast. From here to the summit, we were on the massive Carboniferous limestone containing corals and erinoidal plates, with here and there a Spirifera. The summit of the ridge attained here was considerably higher than that previously ascended, and was evidently as high as, or higher than, any neighboring point north or south. The aneroid barometer indicated that the height was in the neighborhood of 10,000 feet. The higher points of the summit were thickly covered with snow, on which were lying thousands of dead grasshoppers; and in many places we saw the tracks of the grizzly bears which had ascended the range to feed on these insects. The prospect from this point is exceedingly grand and extended. The ridge, as has been remarked, is, at its summit, extremely narrow, coming to a sharp knife-edge, and the view is unob- structed in all directions. Nearly north and south stretch the irregular summits of this rugged range, while on either side the eye sweeps over the open prairie till arrested by the mountains which rise above the plain. To the east, the Crazy Woman’s Mountains are most conspicuous; to the south, the ranges near the Yellowstone River; and westward, the rich Gallatin Valley extends to the “ Meeting of the Three Waters”; and far beyond were the Bitter Root Mountains. At the foot of the abrupt cliffs on which we stood was a little mountain lake, far below us, though seem- ingly at our very feet. With its deep-blue waters, it was prettily set off by the white limestone cliffs above and the dark pines inclosing it on the farther side. The following cut (fig. 10) will give some idea of the general trend of the summit of the range. The points lettered (A, B, ©, D) refer to the cuts which follow, showing roughly the dip of the “aly pod Fort Ellis. strata where indicated. No special importance is attached to these, except as showing the irreg- ularity which exists at different points. The younger rocks lie on the east side, the Carboniferous Fig. 11. sorsspin yt? -snosafruoqand +9n0990} 249 senota,frogtDQ "$N099D7}0L9 pet Y yg? Q a Q 3 gp s = & 3 Qa 3 fos oS & 4 a m. =. By PS > ay a a8 es 8 Pa = e = o 3 & @& 8 5 my Ss ‘2. & - e I ¢ & limestones form the summit, and the older rocks are on the west, with a reversed dip. We were unable to extend our observations below the summit, and hence have nothing to add in this relation to what is given in the reports already referred to. TO YELLOWSTONE: NATIONAL PARK. 121 The following is a list of the fossils obtained during our examination of these mountains, as identified by Mr. Whitfield : Cretaceous, September 4 and 5. Ostrea congesta, Con., associated with fragments of carbonized wood. Jurassic, September 4 and 5. . Camptonectes eatenuatus, Meek. . Camptonectes bellistriata, Meck. . AMyacites (Pleuromya) subcompressa, Meck. . Myalina (Gervillia) perplana, Whitf. (n. sp.). . Gervillia erecta, M. & H. . Gervillia sparsaradiata, Whitf. (n. sp.). . Gryphwa planoconvera, Whitf. (n. sp.). a ~ m Co Le src St Carboniferous, September 4. Summit. . Cyathopylloid coral. . Crinoidal plates. . Platycrinus, sp. ?. . Spirifera centronata, Winch. Limestone interstratificd with the red bands. . Productus nebrascensis, Meek. . Chonetes mesoloba, Norwood & Pratten. . Athyris, sp.?. we Os bo Nao Carboniferous, September 5. Summit. . Oystiphyllum, sp.?. . Campophyllum, sp.?. . Campophyllum torquium, Owen. . Chetetes, sp.?. . Zaphrentis centralis, Ev. & Shum. 2. . Syringopora mult-attenuata, McChes. . Spirifera centronata, Wiuch. Limestone interstratified with the red bands. 8. Spiriferina Kentuckensis, Shum. 9. Athyris planosuleata, Phil.?. 10. Athyris subtilita, (H.) Meek. 11. Rhynchonella Osagensis, Swall.?. 12. Streptorhynchus crassus, M. & W. 13. Productus punctatus, Mart. 14. Productus costatus, Sow. 15. Productus Prattenanus, Norwood. 16. Productus cora?, or perhaps P. Prattenanus, Norwood. 17. Productus, sp.; may be P. nebrascensis, Meek. 18. Chonetes mesoloba, N. & P. 19. Chonetes granulifera, Owen. 20. Euomphalus, sp. AS oR be FROM THE BRIDGER MOUNTAINS TO THE FORKS OF THE MUSSELSHELL. We camped September 5 on Cottonwood Creek, and made from here a short excursion to the west of the road. The main valley of Shields River is a synclival, lying between the Bridger Mountains and the Crazy Woman’s Mountains, with an axis pointing in a direction about north 20° west. In the valley, the rocks are rarely exposed; but riding up tbe creek, two or three miles from the road-crossing, we find the rocks dipping 30° east, with the strike north 30° west. The exposures here show a friable sandstone, disintegrating readily. The rock has a dark, somber appearance, and is made up of a greenish or brownish base, with small grains of quartz and a little 16 Ww 122 RECONNAISSANCE FROM CARROLL, MONTANA, feldspar. For a distance of two miles, the inclination remains the same; the rock standing up in a series of wave-like ridges, all having an abrupt side toward the west, and a gradual slope to the east. Looking from the eastern side, the existence of the abrupt rock exposures would hardly be expected, so gradual is the rise of the grassy slopes. From the west, on the contrary, the eye is immediately struck by the remarkable series of hills with precipitous fronts. Some five miles from the road-crossing, there is a sudden change of dip, and as sudden a return to the easterly direction: this is very probably a local change, occasioned possibly by a dike of igneous rock noticed at that point. The rock is here generally a sandstone, auswering more or less closely to the description given above, sometimes a sandy slate, sometiines a whitish-gray sand- stone. At the headwaters of Cottonwood Creek, about six miles from the road, we found an exposure of a brown sandy slate, full of fucoidal remains, and containing a few indistinct shells. As this rock is apparently one of the lowermost layers in the group of rocks being described, these fossils are ef interest as furnishing a clue to the thickness of the strata. The fossils are very poorly preserved, but have been identified by Mr. Whitfield as follows: 1. Crassatella, sp. 2. Crassatella, near cnough to C. vadosa, Morton, to have come from New Jersey. 3. Inoceramus, sp. 4. Pholadomya, sp. 3. Gryphwa, sp. 6. Panopaa, sp., very near LP. occidentalis, M. & H. 7. Scaphites larveeformis, M. & II. Scaphites larevaformis is regarded as characteristic of Dr. Haydeu’s No. 2. Above this bed there mast be 5,000 fect of rock belonging to the Cretaceous, though referred in part by Dr. Hayden to the Coal Group. At the point mentioned we pass a deep grassy valley a few hundred feet in width, and on the other side rises along range of high bluffs 100 feet above, aud extending for a mile or more (see fig. 12), , The rocks are exposed for a height of from 10 to Vig. 12. dete : 50 feet in the perpendicular eastern front of the bluffs, and form a feature of the country quite conspicuous even from a distance. The rock is 2 a brown and gray sandstone in alternate layers, a eae ae with occasional slaty bands. The dip is here westerly, it being the under part of a very long aud low fold. From the summit, quite a good view is obtained to the west; the bluff hasan abrupt front both to the east and northwest. The valley alluded to occupies the position of the axis of the anticlinal, and the fold itself is a continuation north of the folding which took place in the Bridger Range. Turning north from here, we crossed the divide a mile beyond, and came into a long valley which trends a little west of north. The rock observed here was a brownish-yellow sandstone, with a clay-shale underlying it, aud is undoubtedly Cretaceous, though containing no fossils. The valley alluded to drains into Sixteen-mile Creek. We followed it for a distance of ten miles, keeping along with the strike of the rocks, and found it abundantly covered with thick grass, or rather at this season with hay cured in the ground, which could afford grazing for multitudes of cattle. Turning again easterly, across the strike of the rocks, we cross a long series of wave-ridges dipping _east as before, and much resembling those previously observed. A very white fine-grained sandstone forms a series of bluffs not much west of the road. The valley of the south branch of Deep Creek is wide and level. Ou the northeastern side, where the road to the Forks of the Musselshell turns off to ascend the divide, there is quite a high ridge, extending from the end of the Elk Range across toward the Crazy Womaw’s Mountains. This valley is obviously, like its continuation below, a synclinal, for the strata dip sharply to the west 70°, the strike being the same northwest. The same dark-colored sandstone forms the first layer: this is underlaid by a sandy slate with large clay cannon-ball concretions. From here on for a mile, the dip is continuously westerly, there being the same series of wave-ridges observed before, TO YELLOWSTONE NATIONAL PARK. 123 only here the dip is reversed, and the abrupt side is toward the east. Thestrike remains the same, but the dip is gentler, averaging 40°. After some 5,000 feet of strata, the dip is reversed. An exposure of rock on the east side of the trail shows a laminated sandstone, generally soft and friable, but in some places very hard. The dip of the first layers is 30°, and this increases as we proceed to 45°, the inclination being here toward the east or northeast. A mile farther on, near the head of Flathead Creek, we notice another fold. The rock is here a soft yellowish sandstone, dipping west at a small angle, 15° to 20°. This contained many oval clayey conerctions, and in the seams in the rock there was more or less calcite. Ripple-marks were noticed in one or two places. Still farther on, the opposite side of the fold is seen, and here it appears that the dark-green and gray rocks seen just after leaving the south branch of Deep Creek underlie the soft yellowish sand- stone observed near Flathead Creek. For a mile or two more, we pass over the sandstones, chiefly the dark rock, but occasionally noting beds of the lighter-colored. This latter is much cracked and broken, scaling off into platter-like slabs, so that good exposures of it are seldom seen. Another fold is passed over just before reaching the broad valley of Norton’s Creek. We have thus the indications of three great folds between South Deep Creek and Norton’s Creek, a distance of ten miles in a straight line. The strike varies from north to west, the dip is generally as much as 40°, and sometimes much more. A mile or two before reaching Norton’s Creek, we pass to the left of a high butte formed by three narrow dikes of eruptive rock, seemingly conformable to the sandstone. At Norton’s Creek, the country changes a little more, and we come upon a broad fertile syn- clinal valley. In this neighborhood, igneous rocks, before rare, beome very common, and beds of trachyte and basalt are repeatedly seen interstratified with the sandstones. The most conspicuous example of this is just to the west side of the meadow through which Norton’s Fork flows. Here is a bed of trachyte apparently conformable to the sandstone, and evidently having been erupted between two layers of that rock. It has asemi-columnar structure; the heads of the columns point- ing toward the east, thus appearing as if it dipped west, though in reality the sedimentary rocks have an inclination in the opposite direction. In the broad meadow of Norton’s Fork, a num- ber of isolated buttes of trachyte may be seen; some of these having taken quite peculiar forms. In these folds, it is seldom possible to trace any single layer of rock, because the characters are not distinctive enough; occasionally, however, this may be done, asin the case mentioned above. A care- ful plotting of the successive exposures would doubtless show the continuity of the strata, and give an exact estimate of the thickness of the rocks involved, together with the width of each of the folds. This we were of course unable to undertake. On the east side of Norton’s Meadow, the dip is westerly, and the strike northwest. Here a brown sandstone is exposed, followed by a gray trachyte in beds, which, at a distance, look like a solid sandstone, and might easily be confounded with sedimentary rocks. Opposite where the South Fork of the Musselshell is joined by Flathead Creek, is the extremity of a little range of hills, trending northwest, and forming a sort of spur of the Elk Range, conforming in direction to the low folds we have been tracing, and seemingly like one of them, a little deeper, and having brought up lower strata. Following the sandstone, which is without fossils, we have, as we cross the east end of this hill, some beds of red clay, making a red soil, but not apparently very thick. Above on the hill isa hard, red quartzite, in massive blocks, which are scattered over the surface of the slope. On the east side of the hill, near the creek, we have several exposures of a gray and yellow sandstone dipping east, strike northwest, followed by a reversal of dip in the same beds. Tue rocks here observed are a dark ochery-yellow sandstone, firm, and in rather thick layers, and a whitish sandstone, sometimes in very thin, papery layers, sometimes massive, but not often very firm; much the same association as at Hopley’s Hole. The foldings here are not nearly so extensive as those described before; the thickness of rock involved being perhaps not more than 1,000 feet. Near the hill, the dip is steep; but a mile from it the inclination becomes very gradual, and insensibly the strata subside, becoming nearly hori- zontal. ——— ervey, is See yy RERUN ea ===" Sandstone. At the west end of this limestone wall, a little cafion opens out, showing the considerable thick- ness of the limestone. Lower layers afforded the following fossils, of which a list is here given, with remarks made upon them by Mr. Whitfield : 1. Glauconome, sp.?.— Too indistinct for specific determination.” 2. Productus, sp. ?.—“ This has a feature (elongated depressions) which is seldom seen in rocks above the Chemung of New York or Waverly sandstone of Burlington, Iowa.” 3. Chonetes, sp.?.—Resembles C. granulifera, Owen; also very like C. subumbona, M. & W. 4, Chonetes, sp.— This may possibly be only a variety of the preceding, with which it was associated ; but had I seen only this fossil, I should have thought it Lower Silurian.” 5. Spirifera centronata, Winch. In regard to these fossils, Mr. Whitfield says: “The general expression of these fossils is that of Lower Carboniferous or perhaps Waverly. The locality and formation is worth further exploration in view of the rocks being Lower Carbon- iferous, or possibly even lower.” We ascended the hill at d with some little labor, owing to the thick growth of scrub-pines, with which it was covered, and from it obtained a tine view of the surrounding prairie and the desert country far to the west. The various ranges of hills were distinctly visible: the Judith Mountains with Cone Butte, to the south fifty miles distant in an air-line; the Moccasin Mountains; Bear’s Paw Mountains, and so on. The height of this hill was 3,500 feet above Carroll, or 2,000 feet above the surrounding prairie. Of the general geology of these hills, little can be said from such a survey, except so far as the wide extrusion of the trachyte was noted. The hill in question was made up of the trachyte which had been found in such large quantities over the prairie to the south. This liw 130 RECONNAISSANCE FROM CARROLL, MONTANA, rock is remarkable for its very porphyritic character ; the crystals of orthoclase being very numer- ous and of considerable size, a quarter to half an inch in length. They are usually more or less altered, and under the microscope prove to be made up of minute crystals apparently of a triclinic feldspar, the base consisting of the same material. The whole rock is very white on the fresh fracture; but the little iron it contains oxidizes on expostre, and the surfacebecomes rusty. Descending the hill, we pass south over the terrace mentioned before, which would give a good section of the rocks to one who had the time to examine it with care. The lower portion of the southern face of the hill is precipitous ; the trachyte showing a bold front. Passing from the talus of the mountain, we came upon a series of variegated shales, mostly bright-red, also greenish and blue, evidently baked by the eruption of igneous rock close by; occasional beds of red sand-rock and mud-shales occur with the others. The general strike is shown on the map. The total thick- ness of these sbales was some 800 feet; no fossils were found, only a few indistinct vegetable remains. Overlying these shales,with a slight change of strike, was a thick-bedded sandstone honeycombed, and in other respects so similar to that described as occurring at a, that the identity of the two can hardly be doubted; the underlying shales also correspond. From this point south, the dip became more and more gradual, the terraced hill more grassy, and at d, perhaps two miles from the hills, the dip is reversed, and the sandstone of a and e appears with a slight northerly dip. Still farther south and west, the hills are more broken, and we passed over a series having a somewhat different strike, consisting of a sandstone, then black shales containing large concretions with selenite plates; and, overlying this, other sandstone layers. This shale suggests strongly the Fort Pierre Group, which is seen horizontal only a few miles distant on the prairie. Other expos- ures of sandstone, yellow and granular, were noted at points to the south (see figure); they had a strike and dip as shown in the sketch. These latter are exceedingly similar to those which yielded No. 5 fossils at Box Hilder. No fossils were found, however; though it cannot be doubted that the series of rocks belongs mostly to the Upper Cretaceous. Tnough has been said to show, with the help of the sketch, that the relations are by no means simple. In general, it may be said that the hills, at least at this point, give evidence of folding; the axis lying east and west, so that the uplift- ing force must have been from the south. Our return trip was made by the same trail, and admit- ted of no further observations. VHE GEYSERS OF THE YELLOWSTONE PARK. The route followed by the party in going from Fort Ellis to the Yellowstone Lake and Geyser Basins and returning was that generally taken from this point: through the cation of the East Gallatin River and down the valley of Trail Creek to the Yellowstone River, thence up its valley to the Mammoth Hot Springs, and hence to the falls, the lake, and the geysers. This route has been twice explored by Dr. Hayden and his parties in 1871 and 1872, and the objects of interest in the park have been described in addition in the valuable report of Captain Jones and Prof. Com- stock, who visited it in 1873. It was not to be expected, therefore, that our hurried trip of nine- teen days from Fort Ellis and return would give us any opportunity to collect any important additional facts. It therefore does not seem to us desirable to attempt here an account of the somewhat discon- nected observations we were able to make on our very rapid journey from Fort Ellis to the Geyser Basins, as they must be, in a great measure, repetitious of what has been already published. We may remark, in passing, upon the very great beauty and interest of the whole region, and the wonderful field that it offers for the study of all kinds of modern volcanic rocks. It seems, however, that it may be of some little interest to record the action of the more important geysers as observed by us during the day or two which we spent in the basins. We do this, not imagining that the facts in themselves have any especial importance, except so far as this: that the more the facts in regard to the geysers and their operations are accumulated and recorded, the better will ultimately be the understanding of the phenomena involved. We reached the Lower Geyser Basin the evening of August 20, and, having at that time and during the following morning but a few hours of daylight in all, we saw no display from the more prominent of the geysers of this basin. The only particularly noticeable eruption observed by us TO YELLOWSTONE NATIONAL PARK. 131 was from the “Architectural” Geyser. The discharge took place in the evening, and was repeated again in the morning, lasting each time about 45 minutes. There was no single stream thrown to a great height; but a continued, confused mass of jets was thrown in all directions, with occasional spirts, to a height of 30 or 40 fect. From its very irregularity, it seemed to us one of the most attractive of the sinall geysers. The various other interesting points in the basin, the “Mud Putts,” “ Paint Pots,” ete., were duly examined, but do not need special mention here. We arrived at the Upper Geyser Basin August 21, and remained there until the morning of August 24, or about 60 hours. Our note-book gives the following facts in regard to the eruptions of the more important geysers: Old Faithful, the guardian of the valley, showed a very high degree of regularity during the whole period of our stay. The interval between the commencement of the discharges was 65 or 66 minutes; and, as timed by us for nearly 24 successive eruptions, varied very slightly from this interval. The eruptions were of a very uniform character, differing but slightly in manner or dura- tion (about three minutes) or in the amount of water thrown out. During the night, we were roused each hour by the first rush of the water and steam, and certainly nothing could be more beautiful than this grand fountain in action, illuminated by the light of the full moon. The average height of the column of water, as determined by Mr. Wood, was 115 feet. The solid portion of the geyser, that is, its ornamented crater, has been much injured by the depredations of selfish visitors, who do not realize that the injury to the crater done by them in a few minutes can never be repaired. One of the most interesting features of this geyser, to one who has recently visited the Mammoth Springs, is the great similarity between the step or basin formation bere and that of the caleareous springs, the same cause working here, but under quite different conditions. Bee Hive.—Our camp was situated in a grove of trees on the Fire Hole River, just opposite the Bee Hive Geyser, so that we were able to observe it under very favorable circumstances. During a period of 60 hours, there were three eruptions; the interval between the first and second being 26 hours, and that between the secoud and third 25 hours. ‘The duration of the action was four or five minutes, and the measured height 200 feet. The amount of water ejected is comparatively very small; the apparent discharge being greater than the real. This discharge consists largely of steam, which is swayed in one direction aud another by the wind; the gracefully-waving column of steam and water producing a beautiful effect. Its charms are cousiderably enhanced when the sun strikes the jet so as to produce a rainbow near the top of thecolumn. ‘This geyser has a crater alone; there being no step formation at its foot in consequence of the small amount of water which it throws out. The force of the escaping steam and water is very great, and seems almost to shake the crust in the vicinity. A little attendant geyser at the foot of the Bee Hive acts as a sort of forerunner to it, giving notice by its little stream when its larger companion is about to move. Grand Geyser—We were fortunate enough to see one very fine display of the action of this geyser. It is especially impressive, because of the absence of any elevated crater; the water rising from the very level of the ground. The height of the first discharge did not much exceed 100 feet. It rose to this point in a series of violent pulsations, remained at this altitude for three or four minutes, and then sank back into the pool, which became quite still. A moment later it had com- menced again, the water rising certainly 150 feet by estimate. This again sank down and agaiu rose to its maximum height, and this was twice repeated. Giantess.—The accounts of the eruptions of the Giantess have been so glowing that we were especially anxious to have an opportunity of observing it ourselves. When we arrived, August 21, the crater was quite full and bubbling, seeming to promise a speedy eruption. The following day at 6.30 a. m., it boiled up vigorously, throwing up jets a few feet into the air, exciting hopes that it was about to perform, and bringing those who were in camp somewhat hastily across the stream. At 9o’clock it boiled up again, at times throwing out considerable water, so that it was nearly empty as far as we could see, looking far down into the crater. It rapidly filled, however, and a second outburst on a small scale took place. Two hours later a more vigorous display commenced, the hot water being thrown to a height of 100 feet, by a series of successive irregular throbs, like the beats of a pump; the heavy thumping going on below in a startling manner. This irregular display, extremely interesting and beautiful, yet nothing compared with what the Giantess 132 RECONNAISSANCE FROM CARROLL, MONTANA, is said to do, lasted for an hour; the entire volume of water thrown out being very great. At length, with a sudden burst, the steam drove up the water to a much”greater height than before seen; the noise and concussions accompanying the outburst being very violent. The water was kept at its greatest height for two or three minites, and for this time we found the Giantess all that had been claimed for it. But the reservoir was almost exhausted, and in a short time the only escape was a mass of steam, which rushed out of the crater with a force which no words could describe. After we bad become somewhat accustomed to the noise of the eruption, and the awe inspired by the vast outburst of steam had in a measure subsided, we experimented upon the violence with which the vapor was ejected by throwing into the crater trunks of trees, logs, and other objects which could be found near at hand, and the height to which these were thrown by the escaping steam was a good indication of the force which was being expended. The heavier of these objects Sank nearly to the narrowest part of the crater, and after being held for a moment suspended at this point, rising and falling, according to the violence of the jet which they met, were swiftly shot forth, often rising to a very great height. This steam escape lasted for an hour without any sensible diminution in violevce, and we could not help regretting that all the water had been ejected before the most powerful burst of steam had begun, so that we might have had a full display of the power that was at hand acting on the water. The conception of force given by this great steam escape was perhaps even greater than if it had taken merely the form of a fountain. Six hours later the steam was still escaping, though with somewhat diminished energy, and an occasional liquid jet seemed to show that a little water was draining into the reservoir, only to be immediately ejected. This great steam escape is important as bearing upon the general subject of geysers, showing the vast amount of steam which must be accumulated before the discharge can take place, and the high tension under which it must be. The Castle Geyser was active most of the time during our stay, though with varying force. The amount of water discharged was never very large, and the highest jets did not exceed 50 feet. The Grotto was also almost continuously active, and after seeing the injury done to its crater by visitors, the large majority of whom are residents of the Territory, we could not help wishing that the discharge of boiling water were absolutely continuous, so that the depredators might be kept at a respectful distance. The Saw-mill Geyser played frequently at short intervals, but quite irregularly. The Giunt was quiet, occasional spirts of water to the top of the crater being the only sign of latent energy. GENERAL CONCLUSIONS. DISTRIBUTION OF THE FORMATIONS. Pre-Silurian rocks.—Up to the time when we reached the second Yellowstone Caiion, we had seen absolutely nothing of any rocks older than the Primordial series. This is true, not only with respect to our observations, made in the several minor ranges of mountains, but also includes the inferences to be drawn in regard to the elevated points not reached, from the absence of any crystalline rocks in the local drift. The only exception to this was at Camp Baker, where the drift contained such masses, doubtless from the neighboring Big Belt Range, which we were unable to visit, but in which we should expect to find a considerable development of the Pre-Silurian series. Granitic rocks have been observed by others on the east side of Gallatin River, but they did not appear within the limits of our observations. The inferred absence of crystalline rocks from the minor ranges of hills, which break through the prairie at different points in this part of Mon- tana, for example, the Judith Mountains, the Snow Mountains, Little Rocky Mountains, ete., if correct, would make it improbable that ore deposits of any economic value should be found in them. Silurian.—Primordial series.— We observed strata, proved by fossils to belong to the Potsdam, at two localities, and the relations of the rocks at these points as far as made out have been described ; they may, however, conveniently be recapitulated here. & TO YELLOWSTONE NATIONAL PARK. 133 At Camp Baker, Primordial fossils were found in a limestone hill to the northwest of the Post; the series and the estimated thickness are as follows: Quartzite, 20 feet; variegated shales, mostly bright-red, also green and blue, 150 fect; limestone, in a double series of ledges, 80 feet ; quartzite, reddish, slightly micaccous, then @ series of colored slates, mostly green, followed by shales and thin beds of sandstones and limestones, in all probably 1,500 feet ; still further con- formable shales, 1,000 feet. These extend toward the north farther than we could follow them It is enough to say that the total thickness of the conformable strata underlying the fossil-bearing limestone cannot be less than 3,000 fect, and is probably much more. All the facts point to a very great development of Lower Silurian rocks. The saine rocks were ideutitied at Moss Agate Springs at the south extremity of the Elk Range of Mountains; we found here red shales like those at Camp Baker, quartzite and limestone, the latter containing many fragments of Trilobites. We were able only to glance at this locality, aud consequently the observations stand out isolated. To the Primordial we refer also the rocks underlying (in position overlying, in consequence of au overturn) the Carboniferous limestone of the Musselshell Cation, of which there must be a thickness exposed of some 1,000 feet. It is also very probable that the limestone and red shales of the east bank of Deep Creek observed in iso- lated patches belong to the same time. With the exception of the above, no rocks older than the Carboniferous were seen by us anywhere from Carroll to Fort Ellis. It is certainly not to be affirmed positively that they do not exist in the mountains touched at; the contrary is probable, but it is quite certain that, if present, they are in all cases subordinate. Carboniferous.—Carboniferous rocks are largely and very uniformly developed over this part of the Northwest, as has been remarked by Dr. Hayden. All of the minor ranges of hills, repeatedly referred to, contain Carboniferous limestone to a large extent. In fact, the most striking and char- acteristic features of all these minor ranges are the walls of white limestone, which stand up con- spicuously above the timber, and attract the attention even from a great distance. The very uniform nature of this limestone has been noted, and to its character in weathering out into steep walls and isolated towers is due the conspicuous appearance mentioned. The general facts in regard to this formation, collating those obtained at different places, may be summed up as follows: The upper portion consists of limestone in thin beds, with layers of shale and a little sandy slate. These upper layers contain fossils more abundantly than the following beds. Produetus, Chonetes, Spirifera, Athyris, Rhynchonella, and Streptorhynchus ave abundant forms. At the Bridger Mountains, some bands of red clay in the upper part of the formation were very conspicuous and persistent, and sug- gestions of them were seen elsewhere. At Cinnabar Mountain, in the Yellowstone Valley, the intensely red clays and shale, from which the mountain derives its name, immediately overlie Car- boniferous limestone, and belong, as elsewhere, to the upper part of the formation. Below these irregular, thin beds, showing a somewhat different character at different localities, comes the mass of the limestone already many times described. It is firm, bluish white, and always cherty. The flint is sometimes in uniformly-distributed particles of small size, sometimes in broad bands. When acted upon by the weather, the rock takes the form of vertical walls and steep towers, show- ing no trace of stratification. Reference must also be made to the remarks of Mr. Whitfield upon the fossils found by us at the Little Rocky Mountains. Hesays: “The general expression of these fossils is that of Low Carboniferous, or perhaps Waverley.” To this, we can add nothing, except that the fossils came from a limestone underlying the massive blue limestone before spoken of, con- taining Zaphrentis and other corals in considerable abundance. Hxcept at this point, we found nothing to suggest the possible occurrence of any rocks between the Primordial and the usual Carboniferous. As to the total thickness of the Carboniferous formation as here developed, we can only hazard a conjecture, which cannot be of very great value. The compact limestone spoken of must be at jeast 500 feet in thickness, and the total may be 600 feet. At any rate, it is certain that the deposits point to a uniform condition of things at the time when the formation was laid down. Jurassic.—J urassic fossils were found on the east slope of the Bridger Mountains at both points where the ascent was made. The only rock observed was limestone, and the fossils were quite abundant, in some layers, at least. The thickness seen was small, and on the one side was a Cretaceous fossil-bearing sandstone, and on the other the undoubted Carboniferous limestone. The 134 RECONNAISSANCE FROM CARROLL, MONTANA, interval on both sides was small, aud we should regard an estimate of 100 feet for the total thick- ness as a largeone. Inregard to this, Dr. Hayden says: “The Jurassic rocks are crushed together in the uplift to such an extent that they are quite obscure, and do not appear to much advantage ; but, in Union and Flathead Passes, they are much better exposed.” Lis final estimate of their thick- ness is not clearly stated; but elsewhere, in the same vicinity, he speaks of them as 1,200 feet thick. Whatever may be the facts at this point, we can safely affirm that the development of Jurassic rocks to the north and east is very limited. We had several opportunities for examining beds pos- sibly Jurassic, in search of fossils; but in no case were we successful in our efforts to find such remains. On the contrary, in two distinct localities we passed from undoubted Cretaceous to undoubted Carboniferous, with a very small interval between of non-fossil-bearing strata. These intervening strata may very possibly belong to Jurassic time, and their apparent absence elsewhere may be due to the disturbing influences of the uplifts; but their relative insignificance seems to us quite certain. Banks of red soil were conspicuous at several points, and in appearance suggested, to a certain extent, the “ Red Beds” referred to the Triassic in other localities. Iu three distinct cases, however, we found such layers immediately underlaid by Cretaceous sandstones; so that we think that the beds in question must belong in all cases to the latter horizon. Cretaceous.—To the Cretaceous formation belongs the rock underlying the prairie over nearly all of the route traversed by us. We were unable, however, to obtain any satisfactory results as to the succession of the various beds. ‘The sandstones, of which these rocks for the most part consist, are quite different at the various localities at which they were seen. They are generally without fossils, though frequently containing indistinet vegetable remains, and seem to lack any particularly dis- tinctive or characteristic features. They have been so often described in the preceding pages that it is needless here to enlarge upon them. The lower part of the formation must be that visible on the Bridger Mountains, directly overlying the Jurassic. Very little is in sight, however, and the fossils obtained were very poor. When the rocks appear agaiu in the valley, they are mostly the constantly-recarring “ somber” sandstones. At®the headwaters of Cottonwood Creek (see p. 122), we obtained a few poor fossils in a bed which stratigraphically was the lowest in a series of 5,000 feet involved in a gigantic fold. One of these fossils is credited to Cretaceous No. 2 of Meek and Hayden. From here up, in the order of their time, the rocks have been briefly mentioned. They are mostly dark-colored sandstoues, occasionally shales, aud all nearly destitute of remains of life. The only suggestions of fossils are the indistinct vegetable remains before mentioned, which were found best preserved in the upper strata. The thickness of this Cretaceous series has been esti- mated at 5,000 feet. Most of it is referred by Hayden, though without facts, to the doubtfal “ Coal Group, forming the transition from the Cretaceous to the Tertiary”. We regard them all as properly Cretaceous; in fact, in some of the upper strata, fossils belonging to No. 5 were found. As has already been stated, beds of red clay immediately overlie some of the lowest Cretaceous strata ; and, though their character is probably local and changeable, they are so noticeable where they occur that they deserve mention bere. Cretaceous No. 4.—The most distinctly-marked and characteristic member of the Cretaceous is No. 4, or the Fort Pierre clays, which have already been fully described. Their thickness was esti- mated at 700 to 1,000 feet. They extend from Carroll north and south for a distance of twenty-five miles from the Missouri. Further than this, they were observed below on the river one hundred and fifty miles from Carroll, and from here to the Judith River a distance of two hundred miles. Beds referred to these take part in the uplifted strata, both at the Judith Mountains and the Little Rocky Mountains, overlaid by Cretaceous No. 5. The Fort Pierre clays were not observed at any greater distance from the river than the points mentioned ; aud this is true, although beds both below and above them have shared in the folding near the Bridger Mountains. From this, it is con- cluded that the Fort Pierre clays are limited to the immediate valley of the Missouri at this point, In other words, while the conditions were such as to cause an immense accumulation of mud in what s now the immediate valley of the Missouri, different conditions prevailed at a greater distance from the river, and deposits of sandstone were going on. Cretaceous No. 5.—The Fox Hills Group was determined beyond all question at three points: at Box Elder Creek, near the Judith Mountains; at Haymaker’s Creek, near the Forks of the Mus- selshell; and at the mouth of the Judith River. The rock in each case was a sandstone, which is TO YELLOWSTONE NATIONAL PARK. 135 characteristic of the formation. Upper layers are very yellow and ferruginous, and lower beds white and gray. The local changes are very great. At the Judith Mountains, the thickness of the sandstone, at a point where some estimate of its relation to the underlying clays could be made, was thought to be about 300 feet. North of the Missouri, at the Little Rocky Mountains, sandstones similar to those of No. 5 were seen overlying concretions, and selenite-bearing shales, presumably No. 4; and hence their existence here may be considered probable. If now Cretaceous No. 5 is found at two points, on cvither side of the river, at a minimum distance of twenty-five miles, while between is No. 4, and no trace of No. 5, what has become of the latter? One fact observed may be mentioned in this connection: the dark clays are carried from Carroll one hundred miles and more down the river; and, at some of the lower points, these clays, which appear alone in the immediate river-bank, have a capping at a little distauce of white and yellow sandstone. This observation, made from the deck of the steamboat, is of little value; but it suggests that the No. 5 may be here, where it belongs, directly overlying No. 4, while farther west, in the neighborhood of Carroll, it has been removed by the glacial flood, to be mentioned later. A more thorough study of the Cretaceous beds at the mouth of the Judith would no doubt have assisted us materially in deciding the point in doubt had we been able to give the requisite time to their examination. As it was, the relations of the beds were, as has been said, somewhat compli- cated; and we were able to do no more than to identify by fossils the several members of the group exposed at that point. We found here the Fort Pierre clays in close apposition with rocks containing No. 5 fossils. No. 6. Fort Union Group.—Beds of white sandstone, containing occasional layers of a clayey brown sand-rock, were found at the mouth of the Judith River, evidently overlying the beds of No. 5, before referred to. From these deposits of sand, we obtained the vertebra and long bones of Dinosaurs, identified by Professor Marsh as belonging very near the genus Hadrosaurus of Leidy. With these remains were found Unios, and, in some layers, a little lignite; the general association seeming to refer the deposits to the Fort Union beds. Their thickness was estimated at 400 feet, though no sufficient data were collected to warrant any great confidence in this estimate. Tertiavy.—Distinct tertiary strata were observed in the neighborhood of Camp Baker, and their relations have been so fully described that a repetition is unnecessary. It may be mentioned, how- ever, that the occurrence of a Miocene lake at this point, with beds 250 feet thick, is a matter of no little interest, and opens many interesting questions as to the relations of this with the other well-known Miocene lakes, as also to the Pliocene beds of the Upper Missouri and the Yellowstone Valley. The red and yellow slates, which seem to accompany the Miocene beds of Camp Baker, may possibly be Lower Tertiary, although, as has been remarked, they are not conformable with the overlying beds. In the absence of any decisive facts, however, we must leave this point undecided. Quaternary.—More or less distinct evidence of Quaternary action was obtained at several points. True traveled drift was observed in the Missouri Valley alone. In Upper Yellowstone region, the amount of material transported has been immense; but the action is, comparatively speaking, local. Tine strive, presumably glacial, were seen in the cation above the mouth of Work Creek, and also in the granitic rocks near the bridge. At the latter point, the amount of trans- ported blocks was very large. It may be of interest to note that the blocks apparently from this spot were traced south ; and some few scattered bowlders were seen within 1,500 feet of the top of Mount Washburne, as if the action had been in that direction. This matter has been discussed for this locality by others, and we refrain from carrying it further. The drift at the foot of the Bridger Mountains, the Elk Range, Little Belt Mountains, Snow Mountains, and Judith Mountains, in many cases exceedingly abundant, is in all cases purely local ; almost exclusively Carboniferous limestone or trachyte. The masses and pebbles were distributed in the time of glacial flood, when the flow of water from these hills was very great. The action of this flow of water, in washing out deep valleys, has already been noticed. The special interest attaching to Quaternary phenomena is connected with the facts observed in the Missouri Valley, which have been alluded to, though not described in detail. North and south of the river from Carroll, the prairie is more or less covered with drift-pebbles and masses, whose source is not to be found in the neighboring ranges of hills. On the contrary, the southern limit of this drift is reached 136 RECONNAISSANCE FROM CARROLL, MONTANA, twenty-five miles from the river and about ten miles from the north limit of the Judith Mountains, where the surface-drift changes its character and commences to be made up entirely of trachyte from Cone Butte and the neighboring hills. To the north, the limit is not so distinctly marked ; but it is reached within twenty miles of the river, where the trachyte of the Little Rocky Mountains takes its place. This drift is divided into two classes quite distinct from each other: first, we have the rounded pebbles, very uniformly scattered over the surface of the prairie; and, second, the large, angular blocks distributed here and there at random. The pebbles are generally small, sometimes several inches in diameter, but more frequently much less. They are flattened, quite smooth, and in fact bear much the appearance of common stream-pebbles; they are almost never glaciated. They show, however, the marks of the force of attrition by which they have been smoothed into shape, for the surface-layer of those of uniform texture is curiously marked with semicircular cracks, due to the constant blows which they have received against each other, giving them often quite an ornamented appearance. The material of the pebbles is 90 per cent. quartzite, generally yellow, sometimes dull red (jasper), and also rarely dark-colored. The remaining 10 per cent. is made up of material so heterogeneous that a catalogue of the varieties would be more curious than valuable; pieces of fossil wood, however, must be mentioned. As has been stated, the deposits are superficial in all cases. The material composing the drift of the second class is very generally a bright-red syenite; this forms masses sometimes three or four feet’ in thickness, but averaging about 18 inches. Next in importance is a similar rock, in which the place of the hornblende is taken mostly by black mica; still again, there are masses of black hornblende rock, a grayish syenite, but very little true granite. All these have a very Archean look. Masses of setui-crystalline limestone also occur, though not frequently. These blocks, as has been stated, are uniformly angular, showing little trace of wear. They are less uniformly distributed than the pebbles. The source of these drift masses can hardly be held in doubt. Confined, as they are, to the Missouri Valley, they make it almost certain that they have been brought by running water in the direction of the present stream. In the flood which followed the melting of the ice, which, to a greater or less extent, doubtless covered the higher mountains, and at a time when the land is sup- posed to have been depressed, the waters may well have spread over a width of forty miles, cover- ing the now so nearly level prairie, and could readily have transported the smaller washed pebbles. The large blocks evidently demand stronger agencies, and it is difficult to make any other suppo- sition than that they have been carried by floating ice brought from the westward, from the high mountains which form the main divide of the Rocky Mountains, in which the red feldspar-syenites and the quartzites must have a large development. This would account for their not being rolled bowlders. To the same time of glacial floods belong the formations of the terraces seen ; especially those at the Little Rocky Mountains and Judith Mountains. Our opportunities for making observations above and below Carroll on the river were exceed- ingly limited. Masses of a syenitic rock were observed, here and there, down the river, prominent at the mouth of the Musselshell River, and again at Fort Peck. Running notes from the steamboat- deck have little value, and not much ean be based upon them. Far down the Missouri, near Bis- marek, eight hundred miles from Carroll, the drift bowlders are numerous, and the quaternary sands form deep stratified deposits. These phenomena, however, join on to those which are observed more and more decidedly to the eastward, and the source of which is to be found to the northeast. West of Carroll, near the mouth of the Judith River, the drift just described was not observed. This evidence is negative merely, since, if once deposited as below, it can easily be imagined that subsequent denedation has obscured it. It is interesting to note, in connection with the facts stated in regard to the drift from the westward, the extended and careful observations of a similar character, made at many different points, by Mr. G. M. Dawson, F. G.8., and described in the “ Geology and Resources of the Region jn the Vicinity of the Forty-ninth Parallel,” Montreal, 1875. If the report in question be consulted, a full description of these interesting facts will be found. It is sufficient for our purposes to call attention to the great prevalence of the quartzite drift over the prairie far to the north of the Missouri. The general character of this drift was much the same as that found by us, and it was also referred to the Rocky Mountains as its source. TO YELLOWSTONE NATIONAL PARK. 137 PERIOD OF MOUNTAIN-ELEVATION. Much of the country covered by our reconnaissance is, in some respects, a unique one, as may be gathered from the remarks previously made. The prairie, deeply gullied, as it is, by the Mis- souri and other minor streams, is, in general, of a pretty level character. The strata are horizontal, and there is little evidence of any elevation since those Cretaceous beds were laid down. Above the prairie, at a number of points, rise ranges of hills of no very great extent, and with an altitude averaging about 2,000 feet. They are seen far and near; and, rising blue and misty in the distance, from the dry, parched level, they are a most agreeable relief to the otherwise unbroken monotony of the landscape. They are important as serving to redeem the country from utter worthlessness, since they give rise to numbers of clear, flowing streams. The Judith Mountains, Moccasin, Highwood, Snow, Little Belt, and, north of the Missouri, the Little Rocky and Bear’s Paw Mountains, are the most prominent of these ranges. Rising, as described, from the level prairie, it is to be expected that they would give good sec- tions of the rocks which once lay horizontal over the whole of this part of the country. This would doubtless be true, could the relations be studied in detail in each case. In fact, however, the exten. sive denudation has left only remnants of once extensive formations, so that in a given spot the continuity has been much interrupted. Furthermore, the commonly occurring ejection of masses of igneous rocks has served as a decidedly disturbing element. As to the time when the elevation of our numerous mountain-ridges took place, the evidence, where decisive, points to the same conelusion reached elsewhere in the West, which indeed was to be expected. The time of elevation followed the close of the Cretaceous era. This is clearly seen at the Judith Mountains, where Cretaceous No. 5 has been involved in the general disturbance: The saine cannot be questioned for the Little Rocky Mountains. The elevation of the Snow Mount- ains and the Little Belt Range embraced Cretaceous deposits; and, though it cannot be positively stated that the upper members of the formation came in at these points, this cannot be doubted, in view of the evidence. The Bridger Mountains are the most interesting and satisfactory. Shey include strata from the Primordial to the top of the Cretaceous; all apparently conformable, and all elevated at one time. The junction of the Lower Siluriau with the Carboniferous did not appear in that portion of the range examined by us. At the other points where the Silurian was found, we unfortunately could not observe its rela- tions to the overlying Carboniferous. At the Musselshell Cation, the evidence is not conclusive ; but the relations seem to imply conformability from the Cretaceous down to the Primordial. At Camp Baker, the Primordial stands alone; and we saw no evidence of the Carboniferous following it in the sequence of the strata, as would be expected. This fact strongly suggested to us, while on the ground, an earlier elevation of the Silurian; but this cannot be regarded as of much weight, in view of the fact that the extensive deposits of Miocene Tertiary may well cover up what follows and would otherwise be exposed. 18 Ww é RECONNAISSANCE FROM CARROLL, MONTANA, TO YELLOWSTONE NATIONAL PARK. DESCRIPTIONS or NEW SPECIES OF FOSSILS. BY . R. P. WHITFIELD. DESCRIPTIONS OF NEW SPECIES OF FOSSILS." By R. P. Wuarrrrecp. Genus CREPICEPHALUS, Owen. OREPICEPHALUS (LOGANELLUS) MONTANENSIS, n. sp. Plate 1, figs. 1 and 2. Glabella and fixed cheeks, when united, subquadrangular in outline, contracted across the eyes, and abruptly expanding in front. Glabella narrowly conical, moderately tapering anterior] y, some- what squarely truncate in front, strongly elevated, and gibbous in the middle and along-the central line, marked by three pairs of lateral furrows, which are directed obliquely backward at their inner ends; anterior pair very short, and placed near the anterior end of the glabella. Occipital furrow only moderately strong. Fixed cheek rather narrow, not exceeding one-third the width of the glabella. Eye-lobes proportionally large. Frontal limb long, equaling half the length of the glabella. No perceptible anterior rim can be detected on the part preserved. Ocular ridges distinct. Posterior lateral limbs long and narrow, their lateral extension about equal to the width of the glabella. The species is kuown only by the glabella and fixed cheeks, the latter imperfect; but the form is so unlike any other of the genus described that there can be no difficulty in recognizing it. ‘The extreme elevation of the glabella is a marked feature. Locality and formation—In limestone of the Potsdam Group overlying quartzite near Camp Baker, Montana. Genus ARIONELLUS, Barrande. ARIONELLUS TRIPUNCTATUS, 0. sp. Plate 1, figs. 3-5. Specimens consisting only of the central parts of the head and separated movable cheeks. Glabella conical, the height above the occipital furrow equal to the greatest width at the fur- row; anterior end rounded, as wide as two-thirds of the length above the occipital furrow; margins defined by strong, well-defined dorsal furrows; surface moderately convex, and very faintly angular along the median line; marked by three pairs of very faiut lateral furrows, which are directed obliquely backward at their inner ends; occipital furrow deep, extending entirely across the base of the head; occipital ring moderately strong, and projecting backward in a central spine of unde- termined length. Fixed cheeks narrow and prominent, but rapidly sloping to the margins in front of the small, prominent and somewhat pointed palpebral lobes. Frontal limb short, rapidly narrowing at the sides, in front of the eyes, to the anterior furrow, which is deep and strong; anterior to the furrow the limb is suddenly contracted and subangular in the middle; bottom of the furrow marked be- tween the sutural margins by three deep well-marked pits. Postero: -lateral limbs narrow at their origin, beyond which they are unknown. *The types of all the species here described are in the Peabody Museum of Yale College, New Haven, Conn. 142 RECONNAISSANCE FROM CARROLL, MONTANA, Facial sutures directed forward on a line with the eye for a short distance, when they are directed inward with a strong curvature to the anterior furrow, in front of which they converge more rapidly, and, meeting in the median line, give an angular form to the frontal limb when the movable cheeks are absent. Movable cheeks subtriangular, exclusive of the posterior spine; cen- tral area convex; marginal rim strongly rounded and gradually widening from the front, posteriorly to the origin of the spine, which is of moderate strength, and as long as the glabella and frontal limb of the head. Surface of the movable cheeks covered with strong granules. The glabella and fixed cheeks have been similarly marked, judging from the pustulose surface of the cast of these parts. Thorax and pygidium unknown. The surface-structure, together with the well-marked pits in the frontal furrow, will serve to distinguish this from any other known species. Formation and locality—tIn limestones of the Potsdam Group; at Moss Agate Springs near Camp Baker, Montana. Genus GRYPH AGA, Lam. GRYPH HA PLANOCONVEXA, 0. Sp. Plate 2, figs. 9 & 10. Shell of medium size; general outline more or less orbicular, or with a straightened cardina margin ; transverse section planoconvex. Lower valve more or less rounded, often quite ventricose, but sometimes depressed-convex; beak small and narrow-pointed or truncate, usually somewhat twisted, projecting slightly beyond the line of the hinge, and often incurved close to the cardina} border. Upper valve flat or slightly concave, smaller than the other. Ligamental area of the lower valve small; cartilage-groove narrow. Muscular imprints reniform, eccentric. Substance of the shell rather thin and nacreous; surface roughly lamellose. The form of the shell as seen in several individuals strongly resembles that of an Anomia; but on splitting open one of the specimens, it revealed the features of a Gryphea. The general form and characters are so distinct from any known species from rocks of Jurassic age that it may be readily recognized. Formation and locality.—In rocks of Jurassic age in the Bridger Mountains, Montana; asso- ciated with Camptonectes bellitriata. C. extenuatus, Gervillia erecta M. & H., and Pleuromya subcom- pressa—= Myacites (Pleuromya) subcompressa Meek. Genus GERVILLIA, Defrance. GERVILLIA SPARSALIRATA, nN. Sp. Plate 2, fig. 8. Shell small, much below a medium size, very oblique, and rather slender; the axis of the body of the shell forming an angle of not more than twenty to twenty-two degrees with the car- dinal line. Anterior wing not determined, but apparently very small or obsolete; posterior wing proportionally long and narrow, the surface flattened and -the outer angle very obtuse; body of the shell convex, the left valve much the most rotund, scarcely or not at all curved in its direc- tion. Anterior margin slightly convex; basal margin rounded. Surface of the left valve marked by about five comparatively strong radii, with wider interspaces, those along the middle of the valve strongest and most distant; also by well marked, crowded, concentric lines, which are more distinct in crossing the radii than between, and on the posterior wing are directed toward the hinge in an almost direct line. Right valve less convex than the left and the markings less distinet. This species somewhat closely resembles G. montanensis Meek (Geol. Surv. of the Territ’s, 1872, p. 472), but differs very materially in the smaller angle formed by the body of the shell with the hinge-line, and also in the greater length of the hinge. It is possible it may be only a strongly marked variety of that species, but this can only be satisfactorily determined by more and better specimens. At present, however, it seems impossible to identify it with that one. Formation and locality—In rock of Jurassic age at Bridger Mountains, Montana; associated with characteristic fossils of that formation. TO YELLOWSTONE NATIONAL PARK. 143 Genus MYALINA, De Noninck. MYALINA? (GERVILLIA) PERPLANA, 0. sp. Plato J, fig. 8. Shell rather above a medium size and erect, elongate quadrangular in outline, with a rounded basal margin; anterior and posterior borders subparallel, slightly diverging from the cardinal margin toward the basal line, which is rather sharply rounded ; height of the shell nearly or twice as great as the greatest length in an anterior and posterior direction, and the cardinal border nearly two-thirds as long as the greatest length of the shell. Surface of the left valve very depressed- convex, the anterior umbonal ridge being low and rounded a little within the anterior margin of the shell; beak small, compressed, not projecting beyond the hinge-line. Surface marked by low rounded undulations, on the body of the shell, parallel with the lines of growth, which become sharper thread-like lines along the postero-cardinal border. The depressed and flattened shell, with the subparallel margins aud erect form, will readily serve to identily the species. It is possible that the species may prove to be more nearly related to the genus Gervillia than to Myalina on the examination of other and better specimens; the surface- lining of the shell very closely resembles species of that genus, and the posterior wing is somewhat unlike Ayalina, while its erect form is quite unlike Gervillia. Formation and locality—In rocks of Jurassic age at Bridger Mountains, Montana ; associated with well-known Jurassic fossils. Genus VINNA, Linn. Pinna LUDLOVI, n. sp, Plate 1, figs. 6 and 7. Shell elongate-triangular, very gradually increasing in width from the beaks toward the base ; the dorsal and byssal inargins diverging at an angle of but little more than twenty degrees. Dor- sal margin straight, as long as, or longer than the body of the shell; basal margin, judging from the lines of growth, nearly at right angles to the dorsal margin for a short distance, then directed, with a rapidly increasing curvature, to the byssal border. Apex and umbones unknown. Surface of the valves angularly convex, the left one the most ventricose, and the angularity quite percepti- ble. Both valves are marked, except for a narrow space aloug the byssal margin, by numerous, very distinct, and somewhat flexuous radiating ribs, strongest in the middle of the shell, and decreasing in strength toward each margin; about twenty-two to twenty-four of the ribs may be counted across the middle of the sbell on the specimen figured, most of which are marked along the middle by a distinctly-depressed line. Concentric lines distinctly marked and often forming undulations in crossing the radii. Evidence of minute, scattered, spine-like projections exists upon the surface of the radii. Transverse section across the closed valves angularly elliptical; the relative diameters about as one and two. The strongly-radiated surface and duplicated ribs are features that will readily distinguish this from other described species. Formation and locality.—In limestones of the Coal Measures, in the cafion of the Musselshell, Montana. Genus TAPES, Miihlf. TAPES MONTANENSIS, D. Sp. Plate 2, figs. 1 and 2. Shell small, transversely elongate-elliptical, the length being a little more than twice as great as the height; valves very depressed-convex ; beaks subcentral, a little nearer the anterior end, very depressed and inconspicuous, scarcely rising above the general slope of the cardinal border ; extremities sharply rounded, the anterior end broadest; basal margin broadly rounded, but a little more arcuate than the cardinal border. Surface of the shell smooth, and presenting the appearance of having been polished, with scarcely perceptible lines of growth. 144 RECONNAISSANCE FROM CARROLL, MONTANA, We know of no described fossil shell very closely resembling this one. 7. Wyomingensis Meek is perhaps the most closely related, but differs conspicuously in the position of the beaks, which, in that one, are situated only about one-fourth of the length from the anterior end, while in this they are nearly central. ° Locality and formation.—In Cretaceous strata near the mouth of the Judith River, Montana, in beds apparently overlying the Fort Pierre sbales. Genus MACTRA, Linn. MACTRA MAIA,N. sp. Plate 2, fig. 5. Shell small, subtriangular in outline, with moderately convex valves. Anterior and posterior cardinal slopes nearly equal, the anterior side a little the longest and less abrupt; concave between the beak and the anterior end, while the posterior margin is convex. Anterior extremity narrow, rather strongly rounding upward from the basal margin; posterior extremity subangular; basal line very convex, slightly emarginate just within the posterior angle; beak short, broad, and obtusely pointed, the apex minute, curving, and closely appressed. Body of the shell somewhat regularly convex from beak to base, marked by a strong, subangular, posterior umbonal ridge, behind which the shell slopes abruptly to the margin, and just within which there is a very faintly depressed sulcus extending from below the umbo to the basal line. Anterior umbonal ridge rounded and abrupt. The specimen from which the description is taken is a partial cast, so that the surface is not per- fectly seen; it appears, however, to have been nearly smooth, or with only fine lines of growth. The hinge characters are not clearly made out; the posterior lateral tooth, however, is seen to be long and slender, reaching nearly one-half of the distance between the beak and postero-basal angle: The pallial sinus is somewhat rounded, slightly directed upward, and extends nearly to, or more than one-third of the length of the shell from the posterior end. This species is very similar in general expression to J/. incompta White, MS., but differs in being longest anterior to the beaks, while the reverse is the case with that species. Formation and locality —tIn beds of the Cretaceous formation believed to overlie the Fort Pierre shales near the mouth of the Judith River. Genus SANGUINOLARIA, Lam. SANGUINOLARIA OBLATA, D. Sp. Plate 2, figs, 3 and 4. Shell swall, transversely broad-elliptical or suboval, widest anterior to the middle of the length, where the width is equal to about two-thirds of the length; extremities broadly rounded, the pos- terior one most sharply curved; basal margin strongly rounded, most abruptly so anterior to the middle of its length; cardinal margin much less strongly rounded than the basal border, slightly contracted posterior to the beaks, which are small, compressed, and but slightly projecting beyond the cardinal border. Surface of the left valve very depressed-convex, most strongly curved across the shell from beak t base, and, judging from the form, has been more convex than the right valve; posterior end marked by a very faint sulcus passing from behind the beaks to the postero- cardinal margin. Surface of the shell marked by five concentric undulations and finer lines of growth. Formation and locality.—In sandy limestone of Cretaceous age near the mouth of the Judith River, overlying the Fort Pierre shales. Genus THRACIA, Leach. THRACIA (CORIMYA) GRINNELLI, 0. sp. Plate 2, figs. 6 and 7. Shell of medium size, transversely broad suboval, nearly equilateral, slightly inequivalve, and apparently a little gaping posteriorly. Basal margin of the shell forming a regular elliptical curve TO YELLOWSTONE NATIONAL PARK. 145 between the points of greatest length; dorsal margin less regular than the basal, slightly con- tracted behind the beaks; auterior side somewhat rapidly sloping for two-thirds of the distance between the beaks and anterior extremity ; extremities sharply rounded, a little less abruptly above than below the middle of the height. Beaks of moderate size, rather broad, slightly pro- jecting above the cardinal line, that of the right valve the largest and extending beyond the left. External ligament small, prominent, and situated close behind the beaks. Surface of the valves moderately convex, and apparently a little bent in an anterior and pos- terior direction ; the left valve being the most convex. (This is the opposite from what is usually the case.) Valves marked by distinct but irregular and somewhat crowded concentric undulations, and also by a slightly depressed, oblique, somewhat curving sulcus extending from behind the beaks to the postero-basal border, which it scarcely modifies. Internal features and hinge-structure unknown. The shell bears considerable resemblauce to Thracia Prouti Meek and Hayden (= Tellina Prout M. & H., Proc. A. N.S. Phil., vol. 8, p. 82), but is less contracted posterior to the beaks, and the dorsal margin slopes more rapidly anteriorly, the shell being less full and rounded on this part ; the beaks are also larger, and project above the cardinal line more than in that one; the basal line is also more regularly curved, that one rounding upward more strongly in front and less so behind, giving a straighter postero-basal margin. Formation and locality—tIn rocks of Cretaceous age at the mouth of the Judith River, Mon. tana, which overlie the Fort Pierre shales of that locality. Genus VANIKOROPSIS, Meek. VANIKOROPSIS TOUMEYANA. Plate 2, figs. 11-13. Natica Toumeyana, M. & H., Proc. A. N.S. Phil., vol. viii, p. 270, 1856. Naticopsis ? Towmeyana, M. & H., ib., vol. xii, p. 423.—Meek, Smithsonian Check-List, Ivvert. Foss., p. 18, 1864. "anikoropsis Toumeyana, Meek, Pal. U. 8. Geol. Surv. Territ., p. 332, pl. 39, fig. 2. Shell rather large, naticoid in form, subglobose and a little oblique, composed of about four very ventricose, but not inflated volutions ; spire short, depressed, conical, the slope of the spire inclosing an angle of about one hundred and five degrees ; suture-line deep and well pronounced ; body-volution forming more than two-thirds of the entire height of the shell; aperture broadly oval, rounded, and very slightly extended below, a little straightened on the columellar side, and slightly modified above by the preceding volution ; columellar lip thickened and spreading on the body of the preceding volution, and covering but not concealing the umbilicus, or forming a true callus. Umbilicus small and deep. Surface of the two outer volutions marked by strong, transverse undulations, or ridges, par- allel to the margin of the aperture, and numbering about fifteen on the outer whorl; also, by coarse, revolving bands which cross the undulations and have slightly flattened interspaces ; four of the bands occupying the space of about one-fourth of an inch on the middle of the outer volution. Substance of the shell very thick and solid. When describing this species, we had supposed it to be entirely new, not having recognized it in the description of the imperfect individual used by Mr. Meek; but, on seeing his figure above cited, we suspect it may only be a more strongly marked individual of that species, and, although no direct comparison has been made, we do not hesitate to consider it in that light. It differs, however, in being more elevated and in the stronger vertical folds. Formation and locality.—In beds of Cretaceous age overlying the Fort Pierre shales near the mouth of the Judith River, Montana. 19 Ww EXPLANATION OF PLATE I. CREPICEPHALUS (LOGANELLUS) MONTANENSIS. Fig. 1. View of the glabella and fixed cheeks partly restored in outline..---..----------+----22 eee ee ee eee eee Fig. 2. Profile of the same, showing the elevation of the middle portion ARIONELLUS TRIPUNCTATUS. Fig. 3. View of the glabella and fixed cheeks, showing the form and surface-markings...--..----.--------.---- Figs. 4 and 5. Left and right movable cheeks of the species......---..-+ seb Ge aiteidcaveaiaiacin e ciweieicraereSiSie, sociated Pinna LuDLovi. Fig. 6. View of the right side of the specimen described, showing the radii, with their characteristic duplica- MYALINA (GERVILLIA) PERPLANA. Fig. 8. View of the specimen, with the basal portion restored, according to the lines of growth GRYPHEA PLANOCONVEXA. Fig. 9. View of a lower valve, retaining a portion of the shell and showing the beak. The lower part of the specimen is wholly an internal cast, and shows the form and position of the muscular impression...... Fig. 10. View of the under surface of the specimen as seen when separated from the shell of the smaller valve, showing the cartilage-area of the lower valve and the muscular imprint of the smaller one 143 143 OF FOSSILS NEW SPECIES Plate I. Capt Wm. Ludlow's Exp. to Yellowstone Park,1875. T. Sinclair & Son, lith. Phila. HLM Martin, del. re Brig Gen!AH Derry Conmnmansing Departmené so S s s CY Rpbivai fe A gs ) Ki with ) Creokse eo, - ae eee * (9 my peat tines e peitat Qua J Cnt , H : ’ ey — a | ! ‘ ! : / : Th a 5 : ‘ : \ ey > AIS : “¢ omit NSS 4 YY \ Sp a ees ee \ 5 a rs \ \ a ae a QQ xy YY m \ \ \ Le _ R \ is e \\ \ \ pete Mwshabsh ote Aive : fw —}-——-----_- . ee cee — WOTNGIVIA Gaz | x : fo CAR. YELLO By CAPTAL Publish Missourr sire ” ” Wagon road) AM Benton tos Camplewist Camp baker Lrper Messed eliowstone Yellowstone! Yellowstone « US Land fn = is” ; WP yog* Ei MAP OFA RECONNAISSANCE FROM CARROLL MONTANA TER. TOTHE YELLOWSTONE NATIONAL PARK AND RETURN By CAPTAIN WILLIAM LUDLOW Corps of Fingineers. Chief Engineer Dept.ofDuakota. InJuly August and September 1875. Published by wuthorityof the Han.the SECRETARYof WAR, Office ofthe CHIEFof ENGINHERS,US Army: Sone linch=12 miles 10. = ae o 10 a0 BO rnales Authorities Missourt River owe Bertort Lowe Capt Tining ” aeee ” Wp... Wagon road trom Ft.hltisto mouth oAMbasseishedl Benton toMusselshell R. CampLewis tol Shaw tamplaukerto phos vomits eld eliowstone tokinks of Messedsheld Feliowstone Park ” Yellowstone exd Missouri fivers OS Land Ofice Surveys Compslert amet ctraun ia Chray Nr tire Wit Use (pot Dakota, by TPRoberts Capt LICR LS haley, Lt J Millins 2°Dp Capt CHa 7 Oty: Lt Ldfrgens a ” ” ” ” ” Cpt WA Jones Dr FFHayvden Can NP Raynoleéds AM Bod, tat Wo" (OF mI N. PETERS, PHOTO-LITHOGRAPHER, WASHINGTON, 0 C EXPLANATION OF PLATE II. TAPES MONTANENSIS. Fig. 1. View of the left valve, natural siz6... 6.1 cece cece cece ee cee cee rene cece cece ree ene e ene die aie weiseeei e's Fig. 2. The same enlarged, showing the nearly obsolete strix..... soxibateinleie Sia a! atepnpretsinaiss sisisies jiaswe svete s ciaie Ssieinaa SANGUINOLARIA OBLATA. Fig. 3. View of a left valve, natural size..... aiseeees eraieisee aa pea susmrelnigieemeeing’s oielvlcid| sinkisio’ Gece sLeceuns sSenesisins Fig. 4. View of the same, enlarged to show more distinctly the LOTW sice's sins tne Deus Sereee sedeSacectusearseiece MACTRA MAIA. Fig. 5. View of a left valve, enlarged, showing the general form of the shell, the impression left by the removal of the posterior lateral tooth, and the sinus of the pallial line... 2... 2... eee ee eee cones cece ee ce eeee THRACIA (CORIMYA) GRINNELLI. Fig. 6. View of the right side of the specimen........2-..-.--20+ -2-e ence uececetemeedatness se esieueGteeeteen Fig.7. Cardinal view of the same, showing the bending of the valves............---. sicedoemercedmaioes sieese GERVILLIA SPARSILIRATA. Fig. 8. View of the left side of the specimen described; the posterior end restored in outline........---...---- GRYPHEA PLANOCONVEXA. Fig. 9. Cardinal view of a very convex lower valve, showing the curved beak, which is truncated by attachment to some foreign substance... ...--- 1. ee ee nee eee eee ee eee ee acae Belniais > cine’ Cee Ves SEES Meee ees eseR eS Fig. 10. View of the exterior of same, showing the general form..... isu Skee dee ese dare tees tesa vesmsematen VANIKOROPSIS TOUMEYANA. Figs. 11 and 12. Views of the opposite sides of the specimen described, showing the characters of the shell; the latter figure showing the aperture as seen on the specimen broken and imperfect......---.---..------ Fig. 13. A restored figure, showing what would appear to be the form of the aperture when complete. The umbilicus is shown as seen in the specimen when turned more to the right than in fig. 12 -....-....-.- 144 144 144 142 142 142 FOSSILS- NEW SPECIES OF . Plate Il Capt Wm. Ludlow's Exp. to Yellowstone Park, 1875. T Sinclair & Son. lith. Phila. HM.Martn, del. A. Page. Actiturus bartramius...... sei eerie een ceed 87 Aigialitis montanus . 0.2... 2 ee cece ee eee ee cones 86 VOCHCTUS = whu.c ees) Sieiaenie aja eal dels dew cane 85, 92 Agelaus phoeniceus ... 2.2.22. cece ee nee cen ne eee 78 AlONAIAG ieee wiser eo ele siengigus sag Sac disa teed owen 74 Albee QMOHCOAE esc. o oc dcccee wnelsceceresiqceed suse ence 69, 91 ACCU 2s asc waren ta aeamaratemaecadinatvaaieniereses 80 Alcedo aloyon...-- 2.2 20--.acc00 vencee vaca ce ccceoas 80 Alkaline deposits ...-.. 22-22... e ee eee e eee eee 99 Alluvial clays ...-2. 2. 2-20. eens cece cee Bees 97 Alluvial deposits .......2.. ..0..022 202-222 eee eee 97 Alum Creek 2... 222. eee ee eee eee ee eee eee 23, 62 American Fork, (Musselshell). ........-..--------- 57 American Lanner Falcon. ..--...--.-.---------+-- 82 American Widgeon ......-.....---2--2- 0220-2 -2e- 88 Amethyst Mountain.......--.-. 2-2. ---. 22-2 ------ 30 AMMONUES TAU boa rra spins sisis Geis Week akecewanees 101 AMPCNAG coc ocs% cecescasyweseSeweeeweaseus soawes = 76 Ampelis cedrorum ..--. 22222-2220 s2-06 ges Seeieetsaets os 76 GOT ULUS a soicigad ees ise suey een ae ued eute vices 76 Analysis: Of alkalii:s...c4: isccce sen gece se sepetin sos. 100 Anas DOSsChas, dsici oc cesieeesis ase eGe ashe seecsecie 88 ARGUED) sinjzcesteiecie's. Usps see ec oredss Week tide wanes 88 AN CHUG. snc ioe's os Hae wees, Roe a eee ees Saeasameciaes 101 Anser hyperboreus ..2 22... -2ee wee cee eee e eens 88, 92 Antelop@scssesceea seed wactan Wert peeseseens aos 70 Anthus Ludovicianus 1... 0.200026 022 eee ee eee cee nee 74,91 Antilocapr a americana .... 22.220 --- 262 eens eee 70, 91 Appearance of country near Carroll.........------ 100 Aquila chrysaétos -... 2.22 022-20 ee eee eee eee eee ee 83 Archibuteo ferrugineus ..--.. Saisie adie teisigiee ame ies 83 lagopus sancti-johannis ...--.-.---+------ 83, 92 Architectural Geyser...-.. 22.22. -----2 eee eee ees 131 Arctic Bluebird... ...-....-----------+ eevee e eee ee 73 Arctic Towhee. ..-... 2-2-2. 22-2 cee n ne cee ene cece 78 Arctomys flaviventer ..---.--.- ---+-----+--- Saiiciciees 67,91 Ardea Herodias..... .---+- ---- 222+ wen e eee cee eee 87 ATOGAE? sees ns Se odes sdistione Hatlnae asst Sak aoe 87 Argillitic slate..-.....--.------- ee 22 eee eee eee 113 Arionellus tri-punctatus ..2. 1-0-2 2-20 -0e see ceases 117, 141 Arkansas Flycatcher. .......--. -------+ +--+ +--+ 80 Armes CiGe. coonaw sexe cceseeawes eo Ma ea aew ae 33, 79 Arrow (Creek ccccansccewsvieaws teeeescews veeracais 124 AMOMAG 2. cctcsacece sans boas toes Heke sees ravacine 100 Arvicola riparia ....2. 0-22-0222 nee cee eee eee eee 68, 91 ARSIN ADONIS 6 2c. sca 'e sissecioes oid oeerdeeumece Recess 11, 64 Astronomical observations .....-..--..----------- 38-52 Athyris....-..------- 2 geal bette hie ek oh obhaisars eo SS 113, 121, 133 planosulcata ...--..----- 22-0 eee e ee eee eee 121 subtilita ....-6 Goce eo eaesicraaa sau iaee 121 Audubon’s Warbler......---. 0-2. ---- 2-0-0 eeee ee 74 Aulopora .....---0----- +205 aaa darrian istete Sawasdee odD ANOCOE wea a sacs eae eee cate ce cee se ewce Sele woe ve eae 86 B. Page. Baculites ovatus 2.2.2. .- 2000 cnee cone ceceeenencee 101, 126 Bad Ger soci ctehie nsw eda) tsceseagmer wee semeatence 66 Bad Lands pee susiesctactentais dace cedbewaesseunacaes 13, 73 Baird’s Sandpiper... ....--2- 02-220 cece cee ee cane 86 Baker) Camp: . sraaanoncoanes aacace cee areneeeasemes 89 CHONGIES b5o5. ae dees aacaas meee saa eesanseaeoeneee 129, 133 Butord TMOG 2 syobs escaasoass Gaede cetenue saee 81 GUONUWUP ERE: 2525 2 sae noes cines exces coe a oe 121, 129 Bunting, Black-throated ........-.-----. ee 73 MESOLODE wascce cocrercarcaiaciale aaisisaiavsciee sits 121 Burrowitig OW: s.2.. 2 2sce seiec eee eee iaeees 86 SUDWMNDONG sa vias cca cis cieiwste sieisiete Seaes Hee 129 BUTDNCTEE Kis Seis heer ov oie a sie stare aie s eee ee eas 57 Chordeiles virginianus henryi ..--2.-.2---- 22-2 eee 80 BilleoDOvedls asic we os eee ocieyajeis wate eeeeeeleie le 82 CUR YSO MINIS PINUS s.ccaposasia sii ses ence Saieeisaeasereicise 76 CALUTUS 2.222 ence cee cna ce cuca cncanee 3) 92 CRUST Sisccaiessicty-Grat nataveienwiaiavarsosretdcded isicmictere 76 SLO UISO NOE: a ai Sec pre h BB cee 8 OS eft ek eee Ne hn Sa 82, 92 (OUD. ec ek, dia crecsid DneeAioaveis oooh stele ietlancts 72 Buzzard); Vathkeys sce 2 nee sanesveexeaceeenainsmns + 83 CUNGLUBANERICONUS acacvsedadowe deccigasogegs oes 4 Soe 72,91 C Cinnabar Mountain..........-.2.---------- 002-65 18 : Cinnamon. Bear. cc osegcccauisecciases cagerseses dees 66 Calamospiza bicolor. .... +--+ +020. 022 0 eee eee eee 78 Circus cyaneus hudsonius 2... 0222000222222 2en enone 81, 92 Calista Deweyi...--.-.--- Be ra 126 Cistothorus palustris 2... 0.2.2. .220 cece ee eee eee eee 74,91 Camas Oreely cpnwats seccje hee nysea aciciek oie iandea ava 114, 115 Clageettls aceece cious sad oe se est Boe os ok Se gies 33, 56 Camp Baker .......---.. 2-2-2 0-02 22-2222 .--2+-15, 115 Glark’s Oro seocecece sesicteyceisiae hed eetes we vee 79 Cooke .-- 22. 0.222.022 eee eee eee eee 33, 56 Clay-colored Sparrow ......-.-------2-2+ 2222-02022 77 Lewis .-- +2. 222+ 1202 eee eet eee ener eee 14,107 | Cliff Swallow.......2.222000. ceeeeeecee ceveoe cee z Campophyllum torquium...--. 2.2. 2202.0 202. cee eee 110, 121 CO CR6ble as osc eee A 17 Camptonectes bellistriata.....-. 2-22.22. --2222 000+ 121 “Coal Group” .... 2222. eeeeeeee cece sees cece cess 122, 134 CXEENUOLUS ©... 02. eee ee eee eee ee gize ~ 121 SETI G8 2 ct odoin dta doe a tats edie ATO) Canada Goose .... 2... -2-- 22-20-2222 ence eee 88 Coceygus erythropthalmus ...--2 2.2220 pene ne ween eee 80 TOWNE seee ne cosw heated ieee eae ae wea cae 63 Colaptes ....... sSeeierere ener et emer cn Ng toll, one ihe 80 COMA 02.52 seve snes tinemaswmeeeas cea nee de ene 63 UP OUUG serena armors ata estos raigy diese aes ute a eel 81 CNIS LA ONS 6 ons oc ec amaede sas oa Se os ee nee ee 64, 90 mexicanus.... 2-4 ceen ne eee spe fh ce ears ance 81, 92 occidentalis... ...2. 20-22 cee. eee eee e eee ee 63,90 Cold Spring Creek .......-.2. 022202002. eee ee eee 87 Cafion of Coal Creek......-.2...2.2--..---------- 17 Collurio ludovicianus excubitoroides ....--...-..----- 76 Mirssel8hellll. 2cccic ay acccig opacities ciie'y o's's wee 84 COWUMDING: ceanvonsicmsmmsayavmne! pis ke we eec alent 383 Yellowstone, Grand.........-.....-.---- Q2 COM MDIAE oe oa Gas Rota cee te bits vee cme cletacesiieteds 90 BeCONnd 2c acces Fy ewe oe 18 Colymbus torquatus ...-.. 00222022222 2-2 eee eee eee 90 Caprimul (ld@