Rockhounding in Big Horn County, Montana

2 mapped rockhounding spots in Big Horn County. Most commonly produces agate, chalcedony, fossils, jasper.

Minerals reported in Big Horn County

Standout in Big Horn County

Hand-picked spot in Big Horn County, chosen for unusual mineralogy or documented public access. Each card opens the full coordinates and access notes.

No photo
Top pick
Pryor Mountains
Public
Big Horn County
The Pryor Mountains stand out for Dryhead-style agate, with Mindat listing agate and chalcedony from the range and a named Dryhead Agate Mine in the Bighorn River area. The same Big Horn County country also carries fossil-bearing sedimentary units, so the locality needs careful land-status and fossil-rule checks rather than casual blanket collecting.
Fossils, Agate, Chalcedony, Jasper

Spots in Big Horn County

Spot	Minerals	Coordinates	Access
Big Horn CanyonRoute 211	Agate Chalcedony Jasper Silicified Coral Fossils	45.3130, -107.9604	Public
Pryor MountainsBad Pass Road	Fossils Agate Chalcedony Jasper Petrified Wood	45.2386, -108.2675	Public

Neighboring counties in Montana

Adjacent rockhounding counties, ranked by how close their centroids sit to Big Horn County. A natural extension if Big Horn County is already on your trip plan.

Across the state line from Big Horn County

Rockhounding counties in neighboring states within driving range. Geology rarely respects state borders — these are often the closest mapped spots you can reach without going deeper into Montana.

Big Horn County FAQ

Where can I rockhound in Big Horn County, Montana?+

RockHoundR tracks 2 rockhounding spots in Big Horn County. Each entry below has coordinates, mineral notes, and access type. Always confirm local rules before collecting.

What rocks and minerals are common in Big Horn County?+

Spots in Big Horn County most often produce Agate, Chalcedony, Fossils, Jasper, Petrified Wood. Individual spots can vary widely.

Are these Big Horn 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 Big Horn County rockhounding trip

Open RockHoundR to see these spots on the map alongside land overlays, weather, geology, and your saved finds.