The Slate Range district, in northwestern San Bernardino and southen Inyo Counties, has sometimes been known as the Arondo district. Gold occurs in several places in the Slate Mountains, the principal source apparently having been the Hafford mine. The area is underlain by granite and schist. The deposits consist of narrow quartz veins that contain small but rich gold- and silver-bearing pockets. In places sulfides are quite abundant.
DeGroot, Henry, 1890, Slate Range di5tritt: California Min. Bur. Rept. 10, p. 533.
Tucker, W. B., and Sampson, R. J., 1943, San Bernardino County, Hafford mine: California Div. Mines Rept. 39, pp. 453-454.