By A. H. KOSCHMANN and M. H. BERGENDAHL - USGS 1968
Gold production in San Joaquin County, which has been sporadic, has been entirely from Quaternary placers along the Mokelumne River between Clements and Camanche and along the Calaveras River near Bellota, Linden, and Jenny Lind.
Small amounts of placer gold were mined along the Mokelumne River in the latter part of the 19th century (Clark, 1955, p. 37). From 1918 to 1920 there was a brief spurt of activity, and from the mid-1930's until 1951 several dredging companies worked the placers, especially those in the Clements district. Total production from 1885 through 1959 was 126,400 ounces.
The Bellota district, in T. 2 N., R. 9 E., along the Calaveras River, in east-central San Joaquin County is actually the westward extension of the Jenny Lind district in Calaveras County.
Quaternary gravels have been worked by dredges; however, details on the production and mining history could not be found. In 1959 this district was inactive and had been for several years. The scale of operations in the neighboring Jenny Lind district (Julihn and Horton, 1938, p. 75) indicates that the total production of the Bellota district probably was between 20,000 and 40,000 ounces.
The Clements district is in the northeast corner of San Joaquin County, along the Mokelumne River. The Quaternary gravels were worked on a small scale before 1900; after World War I, dredges were introduced and were very active during the 1930's. Activity slackened soon thereafter, and during 1951-59 the district was dormant. Total gold production is not precisely known but probably was between 50,000 and 100,000 ounces.
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