Rockhounding in San Mateo County, California
3 mapped rockhounding spots in San Mateo County. Most commonly produces agate, chert, chromite, jasper.
Every rockhounding spot in San Mateo County
Coyote PointSan Mateo County, CaliforniaPublic access · Chert, Jasper
Crystal Springs ReservoirSan Mateo County, CaliforniaPermission required · Chromite- Poplar BeachSan Mateo County, CaliforniaPublic access · Agate
Neighboring counties in California
Adjacent rockhounding counties, ranked by how close their centroids sit to San Mateo County. A natural extension if San Mateo County is already on your trip plan.
San Mateo County FAQ
Where can I rockhound in San Mateo County, California?+
RockHoundR tracks 3 rockhounding spots in San Mateo County. Each entry below has coordinates, mineral notes, and access type. Always confirm local rules before collecting.
What rocks and minerals are common in San Mateo County?+
Spots in San Mateo County most often produce Agate, Chert, Chromite, Jasper. Individual spots can vary widely.
Are these San Mateo County rockhounding spots on public land?+
Most spots in this list are tagged public, but access can change with seasons, claims, and local closures. Always verify before driving out, links in the app open the right BLM, USFS, or county pages.
Plan a San Mateo County rockhounding trip
Open RockHoundR to see these spots on the map alongside land overlays, weather, geology, and your saved finds.
