The Naica Extension Mine, formerly called the Felicidad, actually consists of 45 mining claims situated on the Naica Mountain in the state of Chihuahua, Mexico. The Elva Mine includes 42 mining claims, and is also on the Naica Mountain. The Valenciana Mine is in the Santa Eulalia district of Chihuahua, where Spaniards had first found silver in 1591. Other minerals being extracted are lead, gold, and iron.
Reports to investors detailing activities at mines located in Chihuahua, Mexico; chiefly Naica Extension Mine. Mining engineer James V. Dignowity, along with William L. Heyl, wrote these work progress reports, 1935-1936. Small black-and-white photographs depict the area, mining operations, and workers. A map shows the mining claims of the Naica Mining District. Assay/smelting reports are from both the American Smelting and Refining Company, and the Compañia Metalúrgica Peñoles, S.A., 1936-1937. The two reports on the Elva Mine were prepared by Dignowity and Domingo Gallo R. in 1935; the report on the Valenciana Mine, with a short history of the area, was written by mine superintendent John Thiebes, 1936.