Located 18 miles south of Tucson near the Sierrita Mountains and organized in 1877, the Pima Mining District had humble beginnings with several small mining camps.Deposits of copper, silver, lead, zinc and later molybdenum drew an interest to the area, including early operations conducted by the Emperor Copper Co. (1883), the Azurite Copper and Gold Co. (1897), Twin Buttes Mining and Smelting Co.