Location and History
This is an extensive region in northern Riverside and southern San Bernardino Counties. It includes the gold mines just south of the town of Twentynine Palms and the areas to the south known as the Lost Horse, Gold Park, Hexie and Pinon districts. Gold was first mined here possibly as early as 1860, but the most productive period was during the 1890s and early 1900s. There was activity here a.gain in the 1930s, and there has been some propecting since.
Geology and Ore Deposits
The region is underlain chiefly by quartz monzonite and gneiss, with smaller amounts of granite, diorite, and gabbro. Also there are some pegmatite and diorite dikes. The deposits consist of narrow quartz veins containing free gold, pyrite, and often abundant iron oxide. A number of small hut high-grade pockets have been recovered.
Anaheim, Atlanta, Bass, Black Warrior, Desert Queen, Gold Coin, Gold Park Cons., Gold Point, Golden Bee, Golden Bell, Hexie (Hexahedran), Hornet, Lost Horse $350,000, Silver Bell.
Merrill, F J. H., 1919, Riverside County, Pinon Mountain district: California Min. Bur. Rept. 15, pp. 535-536.
Rogers, J. J. W., 1961, Igneous and metamorphic rocks of the western portion of Joshua Tree National Monument: California Div. Mines Spec. rpt. 68, 26 pp.
Tucker, W. B., and Sampson, R. J., 1945, Riverside County, gold: California Div. Mines Rept. 41, pp. 127-144.