Location and History
This district is in north-central Placer County in the vicinity of and south of the town of Gold Run. Extensive Tertiary channel gravels extend from here south to Indiana Hill and the North Fork of the American River. Much of the output in the district has come from the vast Stewart hydraulic mine, which is traversed by U.S. Highway Interstate 80 across its north end. The area was first placer-mined in 1849, and the town was founded in 1854 by O. W. Hollenbeck. The town was originally called Mountain Springs. From 1865 to 1878 approximately $6,125,000 in gold was shipped from the express office here. Mining on a moderate scale continued until about 1915, with considerable production reported in 1908. There was minor work here in the 1920s and 1930s.
Geology
The deposits are located on a major Tertiary channel of the American River that enters the area from the south and continues north to Dutch Flat. The gravel deposits are more than a mile wide in an east-west direction, three miles long in a north-south direction, and up to 400 feet deep. The lower cemented blue gravel yielded as much as several dollars per yard. The upper gravels contain quartz with clay and sand and averaged 11 to 17 cents per yard, while the top gravels ran to four to five cents per yard. Bedrock is slate in the west portion and gabbroic rock to the east.
Bibliography
Anan. July 24, 1875 to Feb. 19, 1876, Hydraulic mining at Gold Run-The Blue Lead ancient river channel: Min. and Sci. Press.
Hobson, J. B., 1890, Gold Run district: California Min. Bur. Rept. 10, p.427.
Jarman, Arthur, 1927, Gold Run: California Min. Bur. Rept. 23, pp.81-86.
Lindgren, Waldemar, 1900, Colfax folio: U. S. Geol. Survey Geol. Atlas of the U. S., folio 66, 10 pp.Lindgren, Waldemar, 1911, Tertiary gravels of the Sierra Nevada, Indiana Hill and Gold Run: U. S. Geol. Survey Prof. Paper 73, p. 145.
Logan, C. A., 1936, Gold mines of Placer County, Gold Run district: California Div. Mines Rept. 32, pp. 62-63.
Lydon, P. A., 1959, Geology along U. S. Highway 40: Mineral Information Service, vol. 12, no. 8, pp. 1-9.
