This district is in southwestern San Bernardino County, in the vicinity of the town of Oro Grande, about five miles north of Victorville and 45 miles north of San Bernardino. The gold mines were active during the 1880s, early 1900s and again in the 1930s. Large amounts of cement are produced here now.
Geology and Ore Deposits
Most of the deposits are in the hills northeast of Oro Grande. According to Bowen (1954), the area is underlain by schist, quartzite and limestone of the Oro Grande series (Carboniferous), dacite, rhyolite, and latite of the Sidewinder volcanic Series (Triassic (?)); and quartz monzonite. The quartz veins are narrow, and the ore bodies usually are small and irregular. Most of the ore has come from the oxidized zone near the surface, but a few high-grade pockets have been found in the veins. The ore contains free gold and often abundant sulfides, including pyrite, chalcopyrite, sphalerite, and bornite. The Carbonate mine has yielded appreciable amounts of gold- and silver-bearing lead carbonate.
Apex, Branch, Carbonate, Dents Grandview Lode, Gold Bullion, Gold King, Oro Grande I and II, Sidewinder, Western States.
Bowen, O. E., Jr., 1954, Geology and mineral deposits of the Barstow quadrangle, California: Calif. Div. Mines Bull. 165, pp. 123-134.