Location and History
Rattlesnake Bar is in northwestern El Dorado County and southern Placer County. The placer mines here along the American River were highly productive during the gold rush. The town was established in 1849 and became good-sized until 1864, when it was destroyed by fire. The Zantgralf mine, the principal lode mine in the district with a reported production of $1 million, was active from 1880 to 1901 and again in the 1930s. Dragline dredging was done in the region during the 1930s. Part of the district is covered by the Folsom Reservoir.
Geology
The district is on the eastern flank of a major granodiorite stock that is intrusive into greenstones and amphibolite. A major body of serpentine and a limestone lens crop out in the area. Several extensive deposits of Pleistocene shore gravels along the American River were hydraulicked. The Zantgraff vein contains abundant sulfides, including galena and chalcopyrite, and was mined to a depth of 1100 feet. This district also has yielded substantial amounts of chromite and limestone and some copper.
Bibliography
Clark, W. B., and Carlson, D.W., 1956, El Dorado County, Zantgraff mine: California Jour. Mines and Geology, vol. 52, p. 429.
Lindgren, Waldemar, 1894, Sacramento folio: U.S. Geol. Survey Geol. Atlas of the U.S., folio 5, 3 p.
