Fossil Hunting in Idaho
Why Idaho?
Idaho is best known for the Hagerman Fossil Beds, one of the most important Pliocene fossil sites in North America, home to the famous Hagerman Horse. However, collecting is strictly prohibited there. For hands-on fossil hunting, Idaho requires more effort. The eastern mountain ranges hold Paleozoic marine limestones with brachiopods and crinoids, and the remarkable Clarkia Fossil Beds preserve Miocene leaves with original pigments still intact. This is a state where knowing geology and navigating remote terrain matters.
What You’ll Find
Paleozoic marine invertebrates dominate what is actually collectible in Idaho. Brachiopods, bryozoans, crinoid stems, and occasional rugose corals occur in Mississippian and Pennsylvanian limestones in the eastern ranges near Bear Lake and in the Lost River Range. The Clarkia lake beds produce spectacularly preserved Miocene leaves, seeds, and insects, though access is limited. Petrified wood occurs scattered across central Idaho’s volcanic terrain. Do not go to Idaho expecting easy collecting; the best material requires remote hiking and geological knowledge.
Best Time to Visit
June through September is the practical window for most sites. Eastern Idaho’s mountain exposures may have snow into June at higher elevations. The Hagerman visitor center is open year-round if your visit is educational. Clarkia area sites are best in summer when logging roads are passable.
Tips for Idaho Collecting
Visit Hagerman Fossil Beds National Monument for the museum and interpretive trails, but understand that no collecting is allowed there. For actual collecting, focus on the Paleozoic limestones in the eastern ranges. Topographic maps and BLM land status maps are essential since Idaho has a complicated mix of federal, state, and private land. Much of the backcountry requires high-clearance vehicles. Rattlesnakes are present in the Snake River Plain area. The Clarkia beds are scientifically significant, so if you gain access, collect responsibly and sparingly.
Collecting Sites
Paris Canyon area
Free Public AccessParis, Bear Lake County
Paleozoic marine limestones in the Bear River Range expose Mississippian and Pennsylvanian invertebrate fossils in roadcuts and hillside exposures.
Clarkia Fossil Beds
Private (Permission Needed)Clarkia, Shoshone County
Miocene lake beds with extraordinarily preserved leaf and insect fossils. Most sites are on private land and require landowner permission.
Hagerman Fossil Beds National Monument
Free Public AccessHagerman, Twin Falls County
World-famous Pliocene fossil site with the Hagerman Horse. No collecting permitted, but the visitor center has excellent displays.
Legal Rules for Idaho
No fossil collecting is allowed at Hagerman Fossil Beds National Monument. BLM and National Forest lands in Idaho allow personal-use collecting of invertebrate and plant fossils. Vertebrate fossils on federal land require permits. Always check land status before collecting in Idaho's complex land ownership patchwork.
Read our full legal guide for federal laws and more details.
Key Geological Formations
- Hagerman Fossil Beds (Pliocene)
- Phosphoria Formation (Permian)
- Wells Formation (Pennsylvanian)
- Challis Volcanics (Eocene)