Cashin Copper Mine, Montrose Colorado
US Geological Survey
 

The Cashin Mine on La Sal Creek, near Montrose. The Cashin hit significantly rich copper-silver ore in 1897.

William A. Farish
May-11-1907

(The Cashin Copper Mine is located on La Sal creek, near Montrose Colorado. The mines comprising the Cashin group were located
around 1880, but no record remains of the original operation. The Cashin was reopened as a group in 1897, but was out of production
by 1902. The following report was writting in 1907 by an engineer representing the mine's owners.)
Abridged Report on the Cashin Copper Mine

By Wm. A Farish, 1907

Property.

The properties consist of the following lode mining claims: Red Chief, Angell, Humboldt, Benn Titon, and Maude, each 300’ by 1500’
and the Cahhin, 300’ by 750’ which are held under U.S. Patent. Also the following claims held by location (now patented) Red Rock,
Red Bird, Horse-shoe, Malachite, and Michigan, each 300’ by 1500’; and the following mill sites; Maude, Red Chief and Titon.

Geology.

The general formation of the country is sand-stone of the Jurassic / Triassic period, of enormous thickness, which is cut to great
depth by the Dolores river, flowing in a northerly direction, and by La Sal Creek, on which your property is located
and by Paradox creek, lying to the north, both of which flow easterly and empty into the Dolores river.

These sandstones dip to the south at an approximate angle of three degrees from the horizontal. On the north side of the
Paradox valley, limestone of a very pure character underlies the sandstone dipping also in a southerly direction. This
together with the fact that the deeper the workings upon your property show an increase presence of lime, would
indicate that the limestone underlies the sandstone in your property and should be reach at a depth of from six to
eight hundred feet below your lowest workings and perhaps sooner. An enormous porphyry dike breaks through the
formation on your property, running in an easterly and westerly direction, as shown by the ground plan map. Now
withstanding its very great strength, it has not faulted or interrupted the continuity of the veins on their strikes in the least.

Veins.

There are three fissure veins upon the property, namely; The Maid vein, the Red Chief vein, and the Horseshoe vein. The
latter seems to be a cross vein, as shown upon the ground plan map and is traced for a distance of over a mile. The former
appear to be the main veins of the country and are traced continuously through the mountains separating La Sal Creek from
Paradox valley, again cropping out in the direct line of their strikes on the north side of the Paradox valley, where they
have again been located. ON the north side of the valley in a direct line with the Maud vein, is the Sunrise mine, which at
the time of my visit was shipping ore to the smelter.

In going south from the paradox Valley the veins converge or come close together and are within a few hundred feet of joining
at the southerly end of the Cashin and Red Bird claims. The above fact, together with the presence of the cross vein (Horseshoe)
and several very powerful feeders which join the main veins in your property, would indicate that the great dynamic forces
which created the fissures had their greatest or concentrated forces in the area covered by your properties. The veins as
stated are true fissures as evidence by the great distance they can be traced upon the surface together with the fact that
they show a great amount of scoria, or what the miners tem “slickensides” at all points upon the walls, and they undoubtedly
go to great depth, cutting all underlying formations. Thy show no faulting or deviation from their strike, running so far as
one can judge, in a direct straight line. The vein filling is a ground up mass of breccia, composed of country rock and silica
which has been cemented together by the sulphide minerals, which in the upper portion of the veins are either oxidized or
leached out. The values were brought into the veins in hot water solutions and gasses, which were generated at great depth by
a porphyritic dike, which created the fissures but which was not strong enough to come to the surface, and were precipitated in
the gangue of the veins as the rock cooled off. This leads to the opinion that porphyry will be encountered in depth.

History.

These mines were discovered about the year 1897, when considerable work was done upon them, and some ore was shipped
from each of these veins (Red Chief, Maude and Horseshoe) by their original owners, of which no record can be had. The Red Chief
mine was worked continuously for several years by the La Sal Copper Mining Company, who acquired ownership from the original locators.
They struck several bodies of high-grade silver ore from which they shipped 2019.53 tons of ore which contained 274,127,304 ounces
of silver, and 236,156 tons of copper ore, of an average value per ton of 135.7 ounces of silver and 11.2% copper.

For details I invite your attention to the annexed smelter returns obtained from the smelters to which the ore was shipped. The silver
sulphides and copper precipitates were obtained from leaching the low-grade ore, the tonnage of which is unknown, the owner having
erected a plant of that character. I am informed that a great many carloads of ore was shipped from the several mines, of which,
as before stated no record can be found.

Development.

The Maude vein has been developed by two tunnels run upon the Titon claim. The lower one starts in about 65 feet above the bed
of La Sal creek and is in a distance of 75 feet. It is badly caved and I was not able to make an examination of it. The other, said to be 100 feet
above it, is run in on the vein for a distance of 390 feet. It shows a well-defined vein. I obtained the following results from assays of samples taken from it:

· At face of tunnel, vein 24” wide, copper 7% silver 7.5 oz.

· 10 ft. south of face, vein 30” wide, copper 10.74%, silver 12 oz.

· 10 further south, vein 36” wide, copper 10.37%, silver 2.4 oz.

· A grab sample taken 56 ft. from the face, representing the best ore gave 14.85: copper and 9.9 oz. silver.

· Two grab samples from the dump, from which the best ore is said to have been assorted, gave No. 1, copper 4.76% and silver,
1.7 oz., No. 2 copper 3.97%, silver 1.90 oz.

These samples indicate the value of the vein.

The Horseshoe vein has been developed by a tunnel located 50 or 60 feet above the bed of La Sal creek, in a northerly direction,
upon the vein, for a distance of 100 feet, from which some good ore has been taken, but it has not been extended far enough to prove the
real value of the property. There is also a tunnel run upon the red Rock, a distance of 50 feet, with the same result. The vein appears
to be from two to four feet wide in both places.

Upon the Red Chief vein a tunnel has been run for 100 feet south. From this tunnel some good ore has been taken but it has not been
extended far enough to get beyond the leached zone. The addit tunnel running north, has been extended 1,240 feet. At a point 7090 feet in
the tunnel, a shaft connects the tunnel with the surface, and a winze has been sunk to a depth of 160 feet and levels started.
This portion of the mine was sampled thoroughly with the following results:

Commencing at a pint about 20’ from the present face of the tunnel samples were taken every ten feet toward the mouth of the tunnel.
Four samples were mixed, from which an assay sample was taken. Therefore each assay represents four samples taken within the number
of feet stated in the list of assays. The result of each assay is multiplied by the width of the vein taken. The total of the multiplication is divided by
the total number of inches samples on the line of the vein. This will give the average value of the ore for the entire length of the vein sampled.

The average width of the vein would be 779 divided by 25 or 31:17’, and the average percent of copper would be 4053:01 divided by 779, or 4.55 oz.

Ore Reserves.

As will be observed, there is no considerable ore in any of the mines that has been developed and blocked out so as to measure and
sample it on three sides, but the great strength of the vein and the persistency with which it maintains its width in all its developments above
and below the addit tunnel, as shown in the rise to the face and the winze sunk from that level, leads to the opinion that it maintains its size
throughout the entire length of the tunnel, both above and below it -- below the tunnel to the depth of the winze and above it to the oxidized zone.

As will be observed from the list of samples taken, pay ore has been established for a distance of 1000 feet upon the line of the tunnel and
to within 25 feet of the surface in the shaft and to the bottom of the winze. I therefore hazard nothing in making the following estimates, which
I consider unusually conservative and absolutely safe: 100 feet above the tunnel level in height 75 ft. below it and 1000 ft. along the tunnel
or in other words we would have 1000 x 175x 2.5 or 437,500 cu. ft. which divided by 12 cubic feet would give 36,458 tons. The present
market value of copper, 24 cts. per pound and silver 65 cts. Per oz. gives an assay value of $27.92 per ton or a gross assay value of $1,017,907
(1907 values) (figuring the full tonnage at 1912 value, silver 56 cts. And copper 12.5 cts., the present value of the ore reserve would be
$746,142.16. Since this report was made the shaft has been sunk to a depth of 152 ft., enclosing at the 100 ft. level and below, native copper
and silver of enormous value. The indications are that the entire vein, extending for miles in either direction, at this depth will average from 60
to 75 percent native copper with very large silver values – (Editor).

Prospective Values.

The prospective values of your property are of the most flattering character. By extending the lower levels already started upon the Maud and
Red Chief veins, north and south of La Sal Creek, a maximum height will be obtained in both direction; upon the Red Chief vein of about 1,300 ft.
By extending the levels already started upon the Maude vein, in the same direction as on the Red Chief, a maximum height of over 1,000 ft. above
the tunnel will be obtained in a northerly direction and fully 1,300 feet in a southerly direction. From the different openings made upon the various
claims covering these veins the indications are that ore chutes will be found at frequent intervals on the lines of the tunnels as they are driven, if
not one continuous and very long ore chute the full distance of the vein.

The Red Chief vein dips westerly at an angle of about 80 degrees from the horizontal and the Maud vein dips easterly at about the same angle.
Such being the case, they would certainly join and form one vein before reaching your southern boundary and continue as such in that direction.

In extending the tunnels in a northerly direction, they will approach the great porphyry dike heretofore mentioned, which runs in an easterly
and westerly direction, which should add values to your veins as you approach it. I however look for your largest and best bodies of ore in
depth. As has hereinbefore been stated, the veins are very deep seated in their origin and undoubtedly cut through all formations, the first of
which, underlying the sandstone, would probably be limestone, in which formation it would be strange indeed if LARGE and ENORMOUS
bodies of ore were not found; but independent of that possibility or more properly speaking, probability after passing in depth below the beds
of La Sal and Paradox creeks, the ore bodies should show less leaching effects and consequently a more uniform value of ore. The very exceedingly
rich copper-silver ores which have been found in the vein, which w ere extracted and shipped will undoubtedly be found at frequent intervals when
the present and future reserves are being stopped out; in fact the assays obtained at the face of the tunnel, namely 4.21% copper and 45.3 oz. silver,
would indicate that you are entering another such body of ore.

Water Power.

La Lal Creek which cuts your property, rises on the eastern side of the La Sal mountains and flows a very large body of water the entire year,
and is about 30 miles in length. The present pipe line which understand is about 2250 feet long delivers water under a 75 ft. head, generating 150
horse power. By extending the distance up La Sal creek any amount, should development work upon the mines be pursed with vigor will be required
for pumping, hoisting and tramming; in fact, to take the place of steam in all departments of mining and reduction.

The portion of the state of Colorado in which your property is located is practically virgin, and has been but little prospected for mineral, it being isolated
and far from railroads. Prospectors are now entering the country in large numbers and from what I learned they are meeting with very encouraging results.
There is an enormous amount of agricultural land, which only waiting for either the government or private capital to utilize the water courses upon it;
therefore, in my opinion it will be only a question of time before a railroad will be constructed from Grand Junction to Durango into this country
passing within a few miles of this property. In fact, the indications are that upon a full development of your property on the lines recommended, and
particularly if you acquire the claims covering the extension of the veins upon which you are located as development upon your own property will justify
it, it will be of itself make a mine that will justify building a road from it to Grand Junction; OR IN OTHER WORDS, SHOULD THIS PROPERTY
DEVELOPE as I believe it will you need give yourself little uneasiness but that a railroad will be built. It is unnecessary to say this road
would be of very great economic value to your property and enable you to produce your copper at a cost not exceeding the average
of the large mines of the United States.

Timber.

The country is heavily wooded with cedar and pinon, suitable for mining purposes. I am told that at the head of La Sal Creek there are
pine forests suitable for lumber.

Cost of Mining.

The cost of mining if the mine is properly handled, developed and equipped as I have suggested, would not be over $3.00 per ton,
including development work, on an output of not less than 300 tons per day.

Estimating the cost of mining at $3.00 per ton, the concentrating at $.75 and the wagon freight, the railroad, freight, smelter charge,
sacks, etc. at a $35.00 per ton, the net profit at the present prices would be $10.57y per ton.

The above estimate is made to show you that under the very worst conditions, a very large profit can be made at the present time.
A very much larger profit will be made in the event that the ores should be change into a heavy iron-copper sulphide upon reaching a
greater depth, which is very probably. This would enable you to smelt your ores direct without concentrating. But upon the building of
the railroad, which I consider an absolute certainty within a year or two, even through the iron ore is not found in your property or in close
proximity to them, the whole proposition will be solved, for high grade iron ore, carrying good values can be bought in adjacent mining camps,
which would not only yield a profit to smelt, but would enable you to smelt your own mines as extracted thus saving a loss in concentration of
$5 to $6 per ton and $20 wagon freight, besides which you would be in a position to market your product as “blister’ copper, requiring no
further treatment. The very large daily tonnage or output of ore which may be reasonably be expected from the mines you now own and other
which you will probably acquire, will enable you to mine and reduce and market the product at a minimum cost.

In conclusion I beg to submit that after considering all the facts an indications connected with these mines which I have endeavored to place
before you in the foregoing report, I am firmly of the opinion that if the mining properties are developed and equipped on the lines suggested,
they will rank among the large and permanent dividend-paying mines of the United States.

(signed) Wm. A. Farish, Denver Colorado, May 11, 19