Custer weekly chronicle. [volume] (Custer City, S.D.) 1890-1931, 1903-10-31
What the Extreme Mining Company are
Doing.

Bank, Mr.. Sours, the artist, and Manager
]. N. Wright, we drove out to the mines
owned by the Extreme Mining company,
most of whom are residents of Washing.
ton, Penn. We arrived about the noon
hour and after partaking of an excellent
repast, prepared by the ladies of the
house, we sailed out to examine the
property, and the following is our report
on what We saw:
The Extreme group of mines are situ-
ated q miles west from Custer, s. D.,
and consist of 81 mining claims which
cover about 320 acres Of mineral ground.
We were in time to witness the finishing
touches of the frame work of the mill
the dimensions Of which are as follows !:
The mill-The main body of the mill
is 26 by 81 feet, to (which is added the
room for the Gates crusher and ore bins
Also the room for concentrators which
is % by 20 feet, and boiler room SO feet
square. The mill is designed for twenty
stamps, ten only of which will be put in
requisition for the present, with stamps
weighing each $50 pounds. The con-
centrators are of the Card pattern, and
each concentrator will make the separa-
ton of the product Of FIVE stamps. The
pulp after passing over the copper plates
which is designed to catch all the free
gold which will amalgamate, passes next
through the Pierce amalgamator which
will not amalgamate on the plates Is de-
signed to catch all the rusty and tarnish-
ed gold which will not amalgamate on
the plates.
The concentrates-The first and heav-
lest portion of the concentrate is an ar.
senical pyrite (misspickeD whi ch is also
the richest in gold, yielding from OF. to
IA OF. of gold to the ton of concentrates.
The second grade of concentratesis is COM
posed mostly of an iron sulphide, and is
not quite so rich i'll gold as the first. The
third is a little lighter material and pro-
portionately lower grade. The
fourth is still lower and runs about OF.
to the ton, while the fifth grade will run
about J an ounce, the gangue matter
left being an excellent cyaniding
ore. The ore which is largely
composed of quartz and siicious states,
will concentrate about 20 into one, while
the shines amount to so little and are so
poor in the precious metal (about 40 cts.
to the tom that it is deemed best not to
waste time by their further treatment.
The Pierce amalgamator--This is a
device placed below the copper tables
and ia designed to collect the particles of
gold which are so fine as to foat on the
water, and in consequence of which 1t
with the quicksilver on the copper plates.
1t would take more space than we can
command to give detailed description
of this machine but suffice it to say that
it does its work well by actual test on
this ore.
Treatment-It is the present design of
the management, after saving all the free
gold which can be saved, land some of
the ore is rich in free gold) to ship the
first and second grades of concentrates
to the smelter. The other and lighter
grades will be saved and piled up to be
eventually treated with the gangue by
the cyanide process which has been
proven by test to be the best adapted to
this material.
The mine-The mine which has thus
far received the principal development
lies about 600 feet north of the mill, and
will necessitate tramway of that dis
tance, until some time in the future
when it is the design to sink vertical
shaft above and nearer the mill. 1t is
presumed at that time that a new and
larger mill will be built as the ore body
is so immense that proper economy
will demand much larger plant. The
present main shaft has attained depth
of SO feet from the bottom Of which
drifts have been run to the north, north
east and east, in all aggregating about lOO
feet. The ore was struck II feet from
the top and it was found to be all ore
from there to the bottom, and how much
further is still unknown as it was all ore
in the bottom of the shaft when the
workmen quit sinking to avoid an excess
of water and commenced explorations
by drifting. The country rock here is
the old micacious slate, (Archean) which
compose the hanging wall while the
character of the foot wall is thus far un.
known. The dip of the vein is about 81
degrees from horizontal and descends
into the earth in southeasterly direc.
ton. The mine is equipped with good
steam hoist and large amount of ore il
piled up ready for milling. The report
that the mine was closed down during
the work on the mill was mistake, as @
small force of men have been employed
on the mine all the time, mainly in the
large open cut and prospect work to i'm.
prove the facilities for taking out ore
when the mill starts.
The buildings-We were surprised to
witness the large amount of work and
buildings since We last visited the mine
A new road has been cut through the
park in which the property is situated
and new bridge has been built across
Ruby creek, which supplies the water
for the mill. There is boarding house
"a by "a built of logs to which frame
addition has been built for wash room
and kitchen. Water for the boarding
house and also the barn is conducted by
pipes from spring and has pressure
of l8 feet and inches when delivered