Welcome to the Mines of the Foresthill Divide interactive map, a comprehensive resource for exploring the historic gold mines of California’s Foresthill Divide, a key region of the 19th-century Gold Rush.
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Interactive Map Guide, Click Here
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Purpose of the Map
The Mines of the Foresthill Divide map is designed to showcase the region’s gold mines and provide detailed historical information about each one. Histories vary from brief summaries to in-depth accounts, depending on available records. This is an ongoing project, with new mines added and existing data updated regularly. To stay informed about updates, subscribe in the “Stay In The Loop” form at the top of each page.
Key Information About the Foresthill Divide
- Geology: The Divide is capped by volcanic andesite, shown as reddish-brown areas on the map. This capping varies from a few feet to hundreds of feet thick, and most mine tunnels begin beneath it.
- Historical Data: The map draws on a detailed 1885–1890 study by USGS Mining Engineer Ross E. Browne, whose 1890 Foresthill Divide map remains highly accurate, as confirmed by modern geologists.
- Boundaries: The Foresthill Divide is outlined in green, based on Placer County data. Most mines are within these boundaries, though future expansions may include the Iowa Hill Divide.
Mine Location and GPS Accuracy
Each mine’s history includes a GPS coordinate for its location. The map will guide you close to the site, but you may need to switch to a GPS device for precision. Accuracy varies:
- Mines we’ve physically verified are accurate within 20 feet.
- Unverified locations may have greater variance, but we’re working to improve precision.
About the Creators
This interactive map was developed by:
- James Robinson, web developer, MountainJoes.com
- Don Robinson, a professional miner and mine educator with 45 years of experience.
Until soon.
Don