Location
This district is in southeastern Stanislaus County. It is primarily a dredging field that extends westward from the town of La Grange along the Tuolumne River for nine miles. This district also includes a dredging field two miles to the south, on an older river channel, and surface "diggings" to the north. The town, originally known as French Bar, was founded in 1852, but the name was changed to La Grange in 1856 in honor of Lafayette's country home. For a time Bret Harte taught school here. The estimated output from dredging is ill million worth of gold.
Geology
The stream gravels in and adjacent to the present Tuolumne River are medium to coarse, loosely consolidated, and average 30 to 35 feet in thickness. The gravels are underlain by tuff. Dredge recoveries during the 1920s averaged 11.6¢ per yard, but later recoveries are believed to have been less. Minor amounts of platinum were recovered. The dredged area is about nine miles long and 1/2 mile wide. A Pleistocene river channel two miles to the south was dredged for a distance of 1.5, miles and is 1/4 mile wide. Here the gravels were compact with a thick volcanic overburden. Thin Eocene gravel patches with abundant quartz boulders and interbedded clay and sand are exposed to the north.
Concerns
La Grange Gold Dredging Co., 1907-42 and 1945-51, one dredge, the longest in the state; Tuolumne Gold Dredging Corp., 1938-43 and 1945-?, one dredge; Yuba Cons. Goldfields, 1941-42, one dredge.
Bibliography
Laizure, C. M., 1925, Stanislaus County, La Grange Gold Dredging Co.: Californio Min. Bur. Rept. 21, pp. 207-208.
Logan, C A., 1919, Platinum and allied metals in California. Tuolumne River: California Min. Bur. Bull. 85, p. 33.
Logon, C. A., 1947. Gold-Stanislaus County: California Jour. Mines and Geology, vol. 43. pp. 92-94.
Lowell, F.L, 1916. Stanislaus County, La Grange Gold Dredging Company: California Min. Bur. Rept. 14, p. 629.
Winston, W. S., 1910, La Grange Gold Dredging Company: California Min. Bur. Bull. 57, pp. 210-211.
