Of the 945 USGS mine records in Shasta County, 585 list gold as a primary commodity. Copper is the most reported primary commodity for non gold mines.
WMH Mine Discovery Tools for Google Earth are available for Shasta county
The USGS gives the following synopsis of Shasta County gold mining history:
Lode and placer gold as well as large amounts of byproduct gold from the West Shasta copper-zinc district have been mined in Shasta County. The major lode districts are the Deadwood-French Gulch, Harrison Gulch, Old Diggings, and Whiskey-town. Placer operations are centered in the Igo district and along the Roaring River.
Total gold production of Shasta County from 1880 through 1959 was 2,033,000 ounces, mostly of lode and byproduct origin. Output of placer gold from 1905 through 1959 was 375,472 ounces. Most of the foregoing production was before 1940; during 1950-59 less than 1,000 ounces per year was reported.
