Location
This is a placer-gold district in southeastern Placer Counry, 25 miles east of Forest Hill. It is an extensive region that includes the Ralston Ridge, Long Canyon, and Nevada Point Ridge areas. It is just south of the Duncan Peak district.
Geology
The deposits are along a west- and south-west-trending Tertiary gravel channel known as the Long Canyon channel, the eastward continuation of the main Michigan Bluff-Forest Hill channel. The gravels are interbedded with rhyolite tulfs and contain granitic boulders. The main Long Canyon channel is fairly broad and flat and covers large areas, but it is generally of low grade. The gold usually is fine. Bedrock is slate and quartz-bearing schist of the Blue Canyon Formation (Carboniferous), with granodiorite to the east. The gravels are capped by andesite and rhyolite. Mining was done by hydraulicking and drifting.
Mines
Blacksmith Flat, Clydesdale, Goggins, Granite, Ralston, Russian Ravine, Zuver.
Bibliography
Lindgren, Waldemar, 1911. Tertiary gravels of the Sierra Nevada: U.S. Geol. Survey Prof. Paper 73, pp. 152-153.
Lindgren, Waldemar, 1900, Colfax folio: U.S. Geol. Survey Geol. Atlas of the U.S., folio 66, 10 pp.
Lindgren, Waldemar, and Turner, H.W., 1894, Placerville folio: U.S. Geol. Survey Geol. Atlos of the U.S., folio 3, 3 pp.
Logan, C. A., 1936, Gold mines of Placer County, placer mines: California Dept. Mines Rept. 32, pp. 49-96.
