Working underground at the San Manuel porphyry copper mine located near San Manuel, Pinal County, Arizona. The mine was in full operation from about 1954 till the mine and smelter closed in 2003. Magma Copper operated the mine before selling it to BHP Billiton. Photo courtesy of the former Arizona Dept. of Mines and Mineral Resources.
Online resources:
Briggs, D.F., 2014, History of the San Manuel-Kalamazoo Mine, Pinal County, Arizona. Arizona Geological Survey Contributed Report, CR-14-A, 9 p. https://library.azgs.arizona.edu/item/AGCR-1552427920122-1
Spencer, Jon E. and others, 2009, Geologic Map of the Mammoth 7.5' Quadrangle, Pinal County, Arizona: Arizona Geological Survey Digital Geologic Map DGM-67, version 1.0, map scale 1:24,000, 20 p. and 2 map sheets. https://library.azgs.arizona.edu/item/ADGM-1566838599531-740
Photographer: Unknown
Photo Date: circa 1970