HISTORY AND GENERAL DESCRIPTION
(July 6, 1943) The Congress Mine was developed by six main shafts the deepest of which (#3) was sunk 4000′ on the incline and altogether there are said to be some 20 miles of underground workings, which are now under water from the 1200′ level.
There are two principal veins, the Congress and the Niagara, nearly parallel and some 300′ apart both striking in an easterly – westerly direction and dipping about 25° to the north or northeast. The width of the Congress vein which lies ,on the contact with the granite and a diorite dike varied from 3′ to 5′, and of the Niagara Vein, a fissure in granite, from 4 to 8′ the length of the pay shoots along their strike never exceeded 650′. The walls of both veins were well mineralized and since the stopes were usually broken 5 to 12 ft wide, lower grade material which would have pulled down the average grade of the vein-ore was either backfilled in the stopes or hoisted to the dumps along with the waste that was broken in the barren sections of the vein and in openings in the country rock.
The old Congress Mining Company operated from March 1891 to the end of 1911 during which period they mined and milled or shipped 692,332 tons of ore from which 388,477 oz. of gold and 345,598 oz. of silver were recovered in bullion. The production from the Congress Vein is given as 370,022 tons with average recovered value of 0.70 oz. per ton and the production from the Niagara Vein is given as 293,220 tons with recovered average 0.415 oz. per ton. The balance came from the Queen of the Hills, or other veins. The average values recovered from the total output 0.561 oz. gold and 0.5 oz. silver. Considering the values which were left in the tailings or
otherwise lost in treatment it is safe to say that the average content of this ore as mined was 0.64 oz. gold and 1.00 oz. silver equivalent to a value of over $23.00 per ton at present prices of metals. (The content have not been verified by Casa for accuracy. It is considered archived historic data, hence are not NI 43-101 compliant. )