Kemmerer

Kemmerer, Lincoln County, Wyoming, sits at the heart of the Green River Formation's Fossil Lake beds — Eocene-age lake sediments famous for exceptionally preserved fish fossils, giving the town its motto "An Aquarium in Stone." Fossil Butte National Monument, 15 miles west, protects part of the same formation. For rockhounds rather than fossil hunters, the area around Kemmerer is also open public land (largely BLM/USFS) for turritella agate (silicified Goniobasis snail fossils), chalcedony, chert, jasper, quartz, and petrified/silicified wood — reasonable hand collecting of this common material is generally allowed on public land here. Fish fossils are a different story: as vertebrate fossils, they can't legally be collected from BLM land, so the well-known fee-dig quarries around Kemmerer operate on leased BLM ground under commercial permits, charging by the hour to split slabs of Eocene fish (Knightia, Diplomystus, Priscacara) out of the tan lakebed shale.

Kemmerer, Lincoln County, Wyoming, on US-30, about 15 miles east of Fossil Butte National Monument.

For rock/agate material: surface collecting on open BLM/USFS ground, hand tools sufficient for common float. For fossils: book a session at one of the area's commercial fee quarries (several operate along US-30 near Kemmerer/Fossil Butte), where staff provide tools and instruction for splitting shale slabs.

Confirm current posted rules and active mining claims before collecting rock material on public land near Kemmerer — always check with the managing agency (BLM Kemmerer Field Office or Bridger-Teton National Forest, depending on exact location) before a trip. Vertebrate fossils (fish, reptiles) may not be collected from BLM land without a permit; use a licensed commercial quarry for guaranteed, legal fossil collecting.