Fossil Butte National Monument

Fossil Butte National Monument in southwestern Wyoming protects exceptionally preserved Eocene fossil beds from the Green River Formation, famous for whole-fish fossils and detailed plant and insect remains. The unit preserves fossil-bearing lake sediments that document life about 50 million years ago.

Museum displays and the visitor center showcase numerous fish fossils and other articulated specimens such as insects and leaves; many are complete and finely detailed. Outdoor trails and overlooks let visitors view the gently sloping buttes and exposures where the lake-bed shales are exposed, and interpretive panels explain fossil collection and the ancient lake environment.

Fossil-rich shales were collected by 19th- and 20th-century fossil hunters and later studied by paleontologists; recognition of the scientific importance of these beds led to federal protection. The monument preserves in-situ exposures plus curated collections used for research and public education.

The monument lies in a rural part of Lincoln County near the town of Kemmerer in southwestern Wyoming, amid basin-and-range terrain and sagebrush steppe. The nearest towns provide services; the site is accessed by paved and gravel roads off regional highways.

• Age and preservation: Fossils date to the early Eocene, roughly 50 million years ago, and include abundant complete fish specimens as well as plants and insects.
• Access note: The park is remote; most visitors combine a stop with nearby Kemmerer or regional outdoor activities in southwestern Wyoming.

What to See #

• Visitor Center and Exhibits: The visitor center displays fossil specimens from the Green River Formation and houses interpretive exhibits about Eocene lake environments and fossil preservation.
• Fossil-bearing strata: Field exposures and quarry sites on park land reveal thinly bedded oil-shale layers that yielded exceptionally preserved Eocene fossils, including many complete fish specimens.