Mount Tobin District
Other Names: Morning View, Miller Basin
Commodities: mercury, antimony, fluorspar, zeolite
The Mount Tobin district is located in the southern Tobin Range, west of Pleasant Valley, and includes the Miller Basin area south of Mount Tobin. Lotz (1934) described a Morning View district in T28N, R40E that would fall into this district.
Lotz, 1934, p. 23; Bailey and Phoenix, 1944, p. 174; Lawrence, 1963, p. 203-204; Johnson, 1977, p. 73
Mountain City District
Other Names: Cope, Rio Tinto, Fairweather, Fair Weather, Murray, Murrey, Sooner, Marseilles, Van Duzer, Van Duzen, Van Duyser, Vanduser
Commodities: copper, silver, gold, lead, zinc, antimony, uranium, tungsten, molybdenum, arsenic
Located on the Owyhee River, 7 miles south of the Idaho state line. The original district name was Cope. The district now includes the old districts of Cope, covering California Creek, Hansen Gulch, Grasshopper Gulch, and Mill Creek; Murray, to the northwest; Sooner, about 10 miles to the east; Marseilles, in section 21, T45S, R53E; the Van Duzer placer district on Van Duzer and Cobb Creeks; and the Rio Tinto Mine area, southwest of Mountain City. The Van Duzer placers are sometimes considered to be a separate district.
White, 1871, p. 59, 61; Wheeler, 1872, p. 34; Whitehill, 1873, p. 23; Whitehill, 1875, p. 31; Angel, 1881, p. 392, 395; U.S. Geological Survey, 1910, p. 654, and 1911, p. 654; Hill, 1912, p. 205; Lincoln, 1923, p. 52, 58; Stoddard, 1932, p. 33; Gianella, 1945, p. 44; Granger and others, 1957, p. 112; Lawrence, 1963, p. 55; La Heist, 1964, p. 66; Garside, 1973, p. 41; Smith, 1976, p. 116; Stager and Tingley, 1988, p. 62; LaPointe and others, 1991, p. 171
Mountain City Placer District Description
On the south side of the Owyhee River, north of Mountain City and Sugarloaf Peak in the Bull Run Range (partly on Humboldt Na- tional Forest land), T. 46 N., R. 53 E.
Mountain City 15-minute quadrangle.
Coats, 1968a, Preliminary geologic map of the southwestern part of the Mountain City quadrangle, scale 1 : 20,000.
From Elko, 87 miles north on State Highways 1 1 and 43 to Mountain City. Placers are on the south side of the Highway north of the town.
Small placer deposits occur along the Owyhee River, north of Mountain City and near Sugarloaf Peak. Grasshopper Gulch (sees. 26 and 35, T. 46 N., R. 53 E.), a north-trending tributary to the Owyhee River, is said to have been placered extensively in the early days of the district, discovered in 1869. Other deposits have been worked along banks of the Owyhee River for a few miles north of Mountain City.
No records of placer production directly credited to this area have been found. Any gold produced from the Owyhee River gravels and reported to the U.S. Bureau of Mines probably was included with production from the Van Duzer district on the south—even though the production was listed under the Mountain City or Cope district name. The placers were worked as early as 1870, when Chinese placer miners were reported to recover $2 to $3 per day per man from gravels on the north side of the river.
The placers in Grasshopper Gulch were worked in the middle 1870's, for about half a mile along the gulch; considerable gold is said to have been recovered. I would estimate that not more than 200 ounces of placer gold was recovered before 1900 and perhaps another 50 ounces since.
The source of the placer gold is small pyritic gold-silver veins in a granodiorite pluton. The age of mineralization is said to be Cretaceous.
Raymond, 1872: Placer-mining activity on Owyhee River; yield per day.
Roberts and others, 1971: Source of placer gold; age of mineralization.
Smith, 1932: History; placer-mining operations on Owyhee River in 1932; source of gold.
Vanderburg, 1936a: Virtually repeats Smith and Vanderburg, 1932: names placer-bearing creeks; history and early production; placer-mining operations and developments in 1932.
Mountain City (Van Duzer) Placer District Description
On the southwest side of the Owyhee River, south of Mountain City at the eastern edge of the Bull Run Mountains, Tps. 44 and 45 N., Rs. 53 and 54 E.
All 15-minute quadrangles—Mountain City, Owyhee, Wild Horse.
Granger, Bell, Simmons, and Lee, 1957, Reconnaissance geologic map of Elko County, Nevada (pi. 1), scale 1:250,000.
Coats, 1968b, Preliminary geologic map of the Owyhee quadrangle, scale 1:31,680.
From Elko, 81 miles north on State Highway 43 to Van Duzer Creek (6 miles south of Mountain City). Placers are along the creek, southwest of the Owyhee River.
Van Duzer Creek drains the low hills west of the Owyhee River for a distance of about 8-9 miles. Most placer-mining activity was concentrated in the upper reaches of the creek where the channel is narrow (sees. 32 and 34, T. 45 N., R. 53 E., Owyhee quadrangle). The gravel is generally less than 15 feet deep and consists of fine-sized granules and subangular and rounded pebbles. The gold varies from fine dust to nuggets weighing 5 or 6 ounces.
The Van Duzer placers were discovered in 1893 by Rutley M. Woodward, who worked the gravels by sluicing and hydraulic methods, reportedly recovering $50,000 in placer gold in the first years following discovery. The placers have been worked sporadically in the 20th century, generally with good returns.
In 1941 the Morrison-Knudsen Co. dredged the placer area from a point 1/2 miles north of the junction with Cobb Creek (NEJ4 sec. 32, T. 45 N., R. 53 E.) downstream about 1/2 miles to farmland (SEJ4 sec. 34, T. 45 N., R. 53 E.), recovering 2,128 ounces of gold. Subsequent operations by different companies in 1948 and 1949 on Van Duzer Creek and Cobb Creek recovered gold averaging 33 cents per cubic yard in 1948 and 70 cents per cubic yard in 1949. Most of the production credited to the "Mountain City or Cope" district by the U.S. Bureau of Mines was recovered from the Van Duzer Creek placers.
The source of the placer gold in Van Duzer Creek is not well known. Small gold veins distributed throughout the Ordovician Valmy Formation probably are the source of the placer gold.
Decker, 1962: States that placer gold deposits in Trail Creek and Van Duzer Creek (north of the Bull Run quadrangle) appear to be spatially related to an exposed thrust surface.
Emmons, 1910: Location; extent of placer; width and depth of placer channel; size of placer gold; source.
Lincoln, 1923: Location; history; geology.
Smith, 1932: History; early production; placer-mining operations in 1932.
Vanderburg, 1936a: Early production; size and fineness of placer gold; source; placer mining in 1932.
U.S. Bureau of Mines, 1941: Dredge operation on Van Duzer Creek described. 1948: Placer operation on Van Duzer Creek; cubic yards mined; amount of gold recovered. 1949: Placer operation at Estella Claim; cubic yards mined; amount of gold recovered.