A number of mining companies owned and operated this mine from 1895 to 1961 including the Theresa Gold Mining Company, the Vidicator Consolidated Gold Mining Company, United Gold Mines Company and Golden Cycle Mining Company. The property was operated through the years alternating with years of idleness.
Records indicate that the mine produced over $2,500,000 in gold or over 120,000 troy ounces, when gold sold for 20.67 per ounce.
The three-compartment Theresa shaft was developed to a depth of 1,620 feet and was serviced by a Wellman, Seaver, Morgan double-drum steam hoist. Power was supplied by at least one 250 Hp Babcock & Wilson water tube boiler. The four-post derrick-type timber headframe stood over the shaft. Rock was transported through the shaft in mine cars on two small, double-deck cages.
The entire surface plant was destroyed by fire in 1934. The headframe was replaced with the present steel structure and the plant was upgraded with a metal hoist house, a metal ore house incorporated into the headframe structure and a new change room.
Additional exploration, carried out in 1961, failed to give promising results and coupled with the closing of the Carlton Mill led to the final closure of the Theresa Mine.