Big Seam mine

Big Seam mine is an underground gold mine in Placer County, California, near Foresthill. MSHA lists its status as active since Jan 18, 2023 and records 8 employees. It is one of 11 gold mines in California that are not marked abandoned, and the only one in Placer County; by employees it ranks 4 of 10 in the state.

Facts

MSHA status
Active since Jan 18, 2023
Type
Underground
County
Placer County
State
California
Land status (BLM data)
Land status not determined in the BLM dataset
Nearest town
Foresthill
Employees reported
8
Operator
Eagle's Nest Mining LLC
Coordinates
39.0203, -120.8181
MSHA mine ID
0404468

Source: MSHA Mines data set, retrieved 2026-10-13. Status and counts can lag real operations.

Land status comes from the BLM Surface Management Agency dataset and can be out of date. Check ownership before you go near any mine site.

History and geology (USGS)

USGS site name
Forest Hill District
USGS status
Past producer
Commodities
Gold, Platinum, Silver, Lead, Iron, Zinc, Copper, Indium
Deposit type
Placer Au-PGE273: Low-sulfide Au-quartz vein
Discovered
1850

Matched by location to the USGS Mineral Resources Data System record 10310614 (retrieved 2026-10-13). The database was last updated around 2011, so history may be out of date.

Gold mines nearby