This district is in south-central Tuolumne County and north-central Mariposa County about 15 miles east of Groveland. The principal sources of gold have been several bodies of quartzitic Tertiary channel gravels that are part of the Tertiary Tuolumne River. The deposits are in the Gravel Range, at Dorseys and north of Smith Station. They were mined chiefly by hydraulicking. Bedrock consists of granodiorite in the east and slate and schist in the west. In places the gravels are capped by andesite.
Lindgren, Waldemar, 1911, Tertiary gravels of the Sierra Nevada: U.S. Geol. Survey Prof. Paper 73, pp. 217-218.
Turner, H. W., and Ransome, F. l., 1897, Sonora folio: U.S. Geol. Survey Geol. Atlas of the U. S., folio 41, 7 pp.