Location
Along the Colorado River from the mouth of the Grand Canyon south to Topock. Tps. 22, 27, 29, N., R. 22 W.; T. 31 N., R. 19 W. (projected).
Topographic Maps
All 15-minute quadrangles—Virgin Basin, Black Canyon, Mount Perkins, Spirit Mountain.
Geologic Maps
Longwell, 1936, Area near Colorado River between Black Canyon and the head of Boulder Canyon (pi. 2), scale 1 in. = about 1 3/4 miles; area near Colorado River between Virgin-Detrital Valleys and head of Iceberg Canyon (pi. 3), scale 1 in. = about 1 3/4 miles; area near Virgin River south of St. Thomas (pi. 4), scale 1 in. = about 1 3/4 miles.
Longwell, 1963, Geologic map and sections of area along Colorado River between Lake Mead and Davis Dam, Arizona and Nevada (pi. 1), scale 1:125,000.
Wilson and Moore, 1959a, Geologic map of Mohave County, scale 1:375,000.
Access
From Kingman, the placers along the Colorado River can be reached by the following routes: To the Temple Bar area—42 miles northwest on U.S. Highway 93 to improved road which leads north about 24 miles to Temple Bar. To the Willow Beach area - 56 miles northwest on U.S. Highway 93 to Willow Beach road; an improved road leads about 4 miles west to Willow Beach placer area.
To the Eldorado Canyon area—46 miles north on U.S. Highway 93 to a dirt road that leads 12 miles west to the vicinity of the placer area opposite Eldorado Canyon. To the Pyramid Rock area—30 miles west on State Highway 68 to Davis Dam; dirt road leads north from Davis Dam about 7 miles to the placer area.
Extent
Placer gold has been recovered from many locations along the Colorado River. Four locations have been described in the literature, and placer gold was probably recovered from other localities as well. Placer gold was found at Temple Bar on the Colorado River north of the White Hills (T. 31 N., R. 19 W., projected; Virgin Basin quadrangle). The gravel containing fine gold was apparently found on both the Arizona and the Nevada side of the river; the gravel bar was inundated by the waters of Lake Mead.
Coarse gold was said to be found at Willow Beach near an outer bow of the Colorado River (T. 29 N., R. 22 W., Black Canyon quadrangle). The bar covers an area of about 250 square feet and rests upon an irregular surface of gneissic granite.
Sand bars opposite Eldorado Canyon on the Arizona side of the Colorado River (T. 27 N., R. 22 W., Mount Perkins quadrangle) contain finely divided gold.
Some moderately coarse gold was recovered from a bench near the river about 2 14 miles north of Pyramid Rock. Apparently, this locality now lies beneath Lake Mohave about 4 miles north of Davis Dam (T. 22 N., R. 22 W., Spirit Mountain quadrangle).
Production History
Recorded production from the Colorado River placers is very small. In 1895 a large hydraulic plant was constructed at Temple Bar, but the enterprise quickly met with failure because of the high cost of transporting materials to the area. Placer gold was recovered from this placer in 1935 before inundation of the riverbed by Lake Mead. According to Wilson (1961, p. 34-35), the placer at Willow Beach was worked before 1900, in 1920, and in 1931, but I have found no production record.
In 1909 a suction-type dredge was installed to work the gravels opposite Eldorado Canyon, but the dredge failed to extract the fine gold on the first try and subsequently was destroyed during the high waters in the spring of 1910. No production record was found for the locality near Pyramid Rock.
Source
The source of the placer gold at these localities is unknown,but the occurrence of gold-bearing lodes in the surrounding region suggests that much of the gold may be locally derived.
Literature
Allen, 1922: Placer-mining operations during the period 1909-10 opposite Eldorado Canyon.
Blake, 1899: Temple Bar placers—operation; grade of gravel; source.
Lausen, 1931: Pyramid Rock placer—notes presence of gold northwest of the Catherine district.
Randolph, 1903: Failure of placer-mining operations at Temple Bar.
U.S. Geological Survey, 1910: Failure of placer-mining operations opposite Eldorado Canyon.
Wilson, 1961: Willow Beach placer—location; extent; type of bedrock; size of gold; source; placer-mining operations; production.
Wilson, 1961: Willow Beach placer—location; extent; type of bedrock; size of gold; source; placer-mining operations; production.
