Newtown is in central El Dorado County 10 miles east of Placerville. It was originally known as Dogtown. Chiefly a placer-mining district, it includes the Camino and Pleasant Valley areas.
Numerous deposits of auriferous gravels were deposited in the west-trending Tertiary channel of the South Fork of the American River. They were mined during the early days by hydraulicking and drifting, and again by drifting through the 1930s. The lower gravels are quartz-rich and in places contain coarse gold. They are overlain by rhyolite and andesite. Bedrock is slate, schist, and quartzite with thin bands of serpentine. Granodiorite crops out to the north and south.
Clark, W.B., and Carlson, D. W., 1956, El Dorado County, placer deposits: California Jour. Mines and Geology, vol. 52, pp. 429-435.Lindgren, Waldemor, and Turner, H.W., 1894, Placerville folio:
U.S. Geol. Survey Geol. Atlas of the U.S., folio 3, 3 pp.