Other Names: Copper Mountain, Cornwall, Cornwall Basin, Mardis
Commodities: gold, copper, silver, antimony, lead, zinc, tungsten, uranium, barite
The Charleston district includes the drainage area of the Bruneau River and its tributaries from Dry Creek, 1.5 miles south of Charleston, to Coon Creek, about 11 miles to the north. First organized as Mardis in 1876 to cover placers on 76 Creek in the vicinity of Copper Mountain, the district also included placers in Pennsylvania Gulch, Union Gulch, Dry Ravine, and Badger Creek. The town of Charleston was founded 4 miles south of the placers.
Hill, 1912, p. 204; Lincoln, 1923, p. 39; Stoddard, 1932, p. 29; Lotz, 1934, p. 18; Gianella, 1945, p. 37; Granger and others, 1957, p. 32; Garside, 1973, p. 42; Smith 1976, p. 35; Papke, 1984, p. 43; Stager and Tingley, 1988, p. 54; LaPointe and others, 1991, p. 56
Charleston Placer District Description
In several gulches on the south side of Copper Mountain, east of the Bruneau River, Tps. 43 and 44 N., R. 47 E.
ount Velma 15-minute quadrangle; Wells 2-degree sheet, Army Map Service.
Goash, 1967, Geologic map of the Mount Velma quadrangle, Elko County, Nevada (pi. 1), scale 1:62,500.
Granger, Bell, Simmons, and Lee, 1957, Reconnaissance geologic map of Elko County, Nevada (pi. 1), scale 1:250,000.
From Elko, 26 miles northeast on Interstate 80 to Deeth. About 8 miles north of Deeth, a dirt road leading from the Marys River Road crosses the low hills; about 38 miles north to Charleston.
Placer gold has been found in Badger, Union, and Seventy-Six Creeks, Pennsylvania Gulch (not shown on maps), and Dry Creek, all southwest-draining tributaries of the Bruneau River, and for an unknown distance along the Bruneau River in the vicinity of these creeks. The placer gravels are as much as 50 feet thick and consist of well rounded pebbles of volcanic rocks and smaller amounts of quartzite and granitic pebbles.
The placer deposits were the first metalliferous de- posits discovered in the area and were presumed to have been found in 1876 because of the name, Seventy-Six Creek, given to the creek. Con- siderable placer gold was recovered from the gravels of Seventy-Six Creek during the years following discovery, but no production records, estimates of production, or discussions of the placers have been found in the literature. I estimate that probably about 300 ounces of placer gold was recovered before 1900.
During the early years of placer-mining activity after 1876, Seventy-Six Creek was most actively worked, but during the 20th century mining has been concentrated in the other tributaries and along the river. In 1907 and in 1932, ambitious plans were made to mine placer gravels on a large scale in the vicinity of Badger Creek and the Bruneau River (sees. 22 and 27, T. 44 N., R. 57 E.) ; these plans were abandoned almost immediately.
Schrader (1923, p. 83) considers the placer gold to have been derived by erosion of small gold veins in Paleozoic sedimentary rocks intruded by Cretaceous granitic rocks in the vicinity of Copper Mountain. The metallization is considered to be related to the Cretaceous intrusions and thus to be of Cretaceous age. Subsequent volcanic activity and erosion of the volcanic rocks probably caused mixing and diluting of the gold-bearing debris; the thick gravel deposits in the area are derived principally from the Tertiary volcanic rocks and contain only small amounts of quartzite and granitic debris from the metallized area.
Coash, 1967: Notes Charleston as placer-mining district.
Lincoln, 1923: Location; history.
Schrader, 1923: Locates major placers; source.
Smith and Stoddard, 1932: History; gold yield per day per man in 1932; placer-mining developments at Earl Prunty Ranch.
Smith and Vanderburg, 1932: Names gold-bearing creeks; lithology and thickness of placer gravels; placer-mining operations in 1907 and 1932; average value of placer gravel at Prunty Ranch.
Vanderburg, 1936a: Virtually repeats Smith and Vanderburg, 1932; reports no development at Prunty Ranch placers; number of men working the placers in early 1930's.