HI, OF OPERATION
OF COPPER MIKES AT BARE HILLS
NEAR BALTIMORE', MD.
One of the first mines opened in this country
with the rurnose of producing copper was the mine at Bare
Hills, Maryland. The m3ne nroduced Biuall amounts of
copper ore. At the start of the Revolutionary War, the
mine ceased operations and remained closed until the year
1845 when operations were resumed on a small scale. The
mine started operations of a large scale in the year 186
and continued operating with a lsr ge output until 1886
at which year the mine was closed because of certain facto --s
'.:■ h made operations difficult. In 19C0, new machinery
was installed and the mine v.as reopened and operated until
1902. Since that time It has been ready to operate at
several times but has never actually been operated.
The Bare Hi 11 mine, while not running now, has
considerable promise of ore; but the low price of copper,
the smal";ness of the deposit and the cost of equipping; the
mine with modern machinery will probably keep the mine
That Maryland was early explored for mineral
wealth Is shov;n by a report on the Province, made in Dec-
ember, 1748, by the Governor and Council to the London
Board of Trade. After the discovery of copper ore at
Bare Hills, a Mr, Jonathon Sleeman, a Corn! shman, bough
the land with the intention of opening a "surface" mln< .
■ject was soon abandoned, very little ore .-•. .-
ly havj ng been removed.
The mine was reopened by Thomas Petheriek about
1845, but wis soon abardoned by him and taken up by a
avis. Petherick had taker; the mine from the owners
under a Gornish lease for twenty-one years, the lease
beinc, of the same type that hns been used for centuries in
England. He sold this lease to Isaac Tyson, Jr., a man
who was attem] I ; to control all of the mines in Maryland,
When Davis' lease exnired, Tyson endeavored to hold the
property under this Cornish lease but after a lonq and
hard-fought lawsuit, the decision was finally rendered
that this form of lease was not binding;. The decision
was due to technical points in the construction of the
lease and the property went back to the original owners.
sina; through several hands, the property came
Into the c^.'ro] of the uare Hill Mining Company,
E BARE HILL .MINIin COMPANY
'■Lhe mines had been worked previously to 1864,
but in that.ye pany began Its most active operations.
The officers of the company were William H, Keener, president,
and Dr. A* P. Dulin, J. Hall Pleasants, John W. McConkey,
C. Oliver O'Lonnell, and George T. Coulter, directoi-s.
The capital stock was #500,000. In 100,000 shares. Pew
mining companies have commenced operations und*r circumstances
so favorable as those which characterized the Bare Hill Co.
The richness of the vein was shot the state-
ment of an expert, who r< that in the 600' level the
ore was 180' long, 60 ' high, and 3' thick. The
ie 500' level were 30' by 80' by 2 l/?', and in the 450'
level 80' by rsO' by 2 l/£" . At this time there was In sd ?ht
1000 tons of ore, worth at ruling prices $140,000. and the
engineer added that bis only regret was "to find a mine, with
such masses of ore exoosed, worked on too small a scale,
and to meet a few miners where scores could find profitable
employment". Another engineer calculated that #9,000, worth
of ore per month could be sent to the market, and more
recent investigators have given the opinion that the richest
and largest deposits have never really been touched.
OUTFUT OF THE MINE
According to Dr. Lehmann, of Baltimore, this mine
was operated almost continuously from 1866 to 1886, the
entire output going to the Baltimore Copoer Works, the
sampling and assaying of the ore being under Dr. Lehmann's
supervision. The records of both his office and of the
copper company vie re destroyed by the great Baltimore fire,
but the old samples, labels, and memoranda at hand enabled
him to give the following rough estimate of the total out-
Prior to 1866, the yearly shipments varied between
2,000 and '5,500 tens of 15 to 20 percent ore. From 1866 to
1876 the annual output was from 800 to 1200 tons of "cobbed"
ore, averaging 18 percent copper, with 1,000 to 1,500 tons
of "hutched" ore or concentrates. From 1876 to 1886 the
shipments gradually lessened, being al 60 tons a month
of 18 percent "cobbed" ore from 1883 to 1886. Taking the
average of these figures, the total output from 1066 to
1886 is about 32,500 tons of 18 percent material. At 15
cents a pound for copper, this represents a gross valuation
of $54. per ton, or a tota] value of $1,755,000. According
to the Tenth Census, the mine in 1880 yielded 17 tons of
concentrates, from which 1,275 pounds of copper were prod-
The mines were profitably operated until 1886,
when legislation by Congress in the special interest of the
companies owning the Lake Superior Copper-Mines forced the
Bare Kill corporation to suspend work.
The mine was not in operation for the 15 years
between 1886 and 1900. At the last named date a stock
company waa formed to reopen the property, new machinery
w-is Installei md the mine was unwatered. The mine was
reopened to fill an order for copper sheathing for a fleet
of ships operating to and from Pa] ti more, after the order
was filled, there being no further orders in sight, the
property waa sold under a deed of trust.
In 1905 the mine was in the possession of I .
Herbert Brown, who waa preparing to unwater and work the
property. Having no orders in sight, Brown sold the mine
to a Mr. Hill who left the mine to its present owner,
Miss Elizabeth Hill.
The deposit, according to old descriptions, was
in a vein which carries calcopyrite, bornite, an< etite.
Unfortunately the material on the mine dump has so succumbed
to attacks of the weather that ore and gangue minerals
sufficiently fresh for microscopic study could not be ob-
The denosit occurs in a general region of horn-
blende schist, probably an altered gabbro. The 2 to 5' vein
is an inter banded layer of amphibole in gray gneiss. The
gangue is black amphibole schist. A few hundred yards to
the east lies a small serpentine mass that has been intruded
o the schia . The ore is apparently in a vein con ! ng
in strike to the schiatoaity of the rocks. The vein she-
movement and crushing.
■ior to the finding of the richer deposits
of Michigan, Arizona, and Montana, Maryland ores were
sufficiently significant to make the state of some im-
portance as a copper producer. Very little ore was actually
removed from the oare Hills mine prior to 1864, At this
time the Bare Kill Mining Company started its operations.
The machinery at that time was very crude, assays
were unreliable, and had to he worked in a semi -rural way,
the miners farming :r good weather grid minir
The ore vein, having an average thickness of 5*
and said to have yielded 11 1/2 ] at copper, had been
developed by an incline shaft following dowi '. e dip of
degrees to a ■ h alons: the incline of 832 feet. The
main shaft was braced with 8" by 8" timber at frequent
iervals by ordinary methods of bracing. Iwo other shafts
were used for bion* Drifts were run at frequent
intervals and the ore re From the drifts was carried
to the main shaft where it wis dumped into small carts,
Ihe carts ran on small tracks, about 2 feet wide, the power
necessary to pull them out of the mines being furnished by
The material taken from the mine was crushed and
the copper ore removed from the gangue. The ore also
— r 7_
contained small amounts of gold 'and silver but it v
not known at tbe time. It is an often told story that
the slag left over, after the copper was removed, was
used to build houses for the workers of the Baltimore
Copper V.'orks at Csnton. IVher it became known that the
ore contained rrold and silver, the houses were demolished
and the valuables removed.
Production continued until 1886, when .the
mine was closed because 6f reasons mentioned before.
When the stock company took over the property
in 1900, it equipped the mine with all necessary surface
buildinqs, boilers, an air compressor, an old-fashioned
hoisting engine, a Cornish pump, and a crusher.
th the introduction of the new equipment, the
mine was operated with s nuch greater efficiency. Practi-
cally all of the intervening ore between the drifts was
stoped out. The material was removed from the mine in
the same manner 93 described before, by mules pulling the
carts out. Other shafts, much smaller, were sunken in the
same vicinity but no trace of these could be found.
The Cornish pump was used to unwater the mines,
ill of the material that was mined was run through
the crusher, the copper bearing minerals then being removed
and the rals being dumped on the dump heap.
This company continued just aa the bnre Hill Mining Company
and shipped all of its copper ore to the Baltimore Copper
Al though the mining company had operated with
much more efficiency than anyone who had previously worked
a, th< downfall of the price of copper, and
the end ins of the contract to supply copper sheathing for
the heats, ended the actual operating life of the Bare
Hills mine for all time.
When Mr. Herbert Brown came, into possession of
the mine in 1905, he had the intention of resuming opera-
tions, but being unable to cope with his adversaries in
business, he dismantled all of the mining machinery and
'DESCRIPTION OP Mil ME
The Bare Hills copper mine is situated on the
summit of a ridge -immediately west of Jones Palls and
about 1 1/2 to 2 miles north of
Mt. Washington, in Baltimore
County, Md, The last build-
ing that whs actually of use
in mining was burned to the
ground several years ago. This
I lding had housed the crusher,
boiler, and steam eneine. In
the accompanying illustration,
the concrete foundation can
r eadily be made out.
Also readily noticed are the large steel stay-
rods that were used to hold the crusher in piece. The:
'rods were ? inches in diameter with large thread,
end where the nuts and washers were nlaceci. This sturdy
construction was necessary because of the consistently
■'■■■! jarring action of the crusher. Wo remains can be
found of the previously mentioned Cornish pump that had
been used to unwater the well.
The main shaft of the mine, pictured above, has
already been filled to within a few feet of the top to rid
the neighborhood of the danger of anyone fa 11 ins into it«
Some of the timber reinforcing can still be noticed.
Judging from what can still be seen of the timber, the
shaft must have been at least 10 feet square. No remains
of the tracks out of the shaft can be found. The ventilat-
ing shafts were: also- completely obliterated.
The picture shown above is that of the mine
dump where the gangue mineral was thrown after passing
through the crusher to remove the ore. Due to not know-
ing the depth of the dump, an estimation of the amount
of waste could not be ascertained. Judging from the
size of the predominating lumps of the gangue, the crusher
must have done a fairly good job.
The office used by the company when operating
from 1900 to 1902 is shown on the following page. When
used by the company it was a one room structure, the size
being 15 feet square. Since then, however, there have been
two additions to the building. 'j,he concrete floor, on which
the safe stood, is still in the same condition as it was
originally. No records of any business transactions
could be found, the records of the old company having
been destroyed in the Baltimore fire, and the records of
the new company were not preserved.
The office, crushing shack, and main shaft
of the mine are all very close to each other, the remains
of the sh*-ick being 50 feet away from the shaft and the
office being 50 feet further
ty in the same general dir-
ection. The mine dump is lo-
cated ris;ht next to the shaft.
The only disadvantage in loca-
tion was that the Baltimore
Copper Works, which removed the
metal from the ore, was located
at Canton, approximately 15
mllos away from the m3ne.
Wh1 le the work of
the mine itself was insignifi-
cant as compared with that of
the Western mines of today, it
doubtless represented, in its day, no mean engineering and
Since all of the mine records vere destroyed,
credit for all of the information Is due the following
men and authors of the publications:
Keyser, R. B. - Copper. In Maryland, Its Resources,
Industries and Institutions, pp. 114, 135, 189.%
Weed, W. H. - The Copper Mines of the World,
pp. 268, 1908.
Overbeck, R. M. - Copper Ores of Maryland.
Maryland Geological Survey, Vol. I, pp. 226, 1897.
Weed, W. H. - Copper Deposits of the Appalachian States,
. pp. 64, 65, 1911.
Professor Joseph T. Singeweld, Jr.
Mr. Donald Coale.
Dr. J. J. Rut ledge, Chief Engineer, Bureau of Mines.
Photographs and description by author.