Fossil Butte National Monument • Wyoming

A dark brown, football-shaped fossil fish with a fan-shaped tail and spines standing up on its back.

Hills with tan and red sediments partially covered with green vegetation.

A fossil frog facing left with its back legs splayed out.

The moon over a snow-covered butte

A dark brown, long, thin fossil fish with a forked tail

A green valley with a ridgeline across the way with a tan top not covered with vegetation.

A fossil of a turtle with a short tail about the same length as the legs

A butte with sagebrush and blue flowers on long stalks in the foreground.

In the ridges of southwest Wyoming are some of the best-preserved fossils in the world. They tell the story of ancient life in a warm, wet environment in and around a freshwater lake. Stingrays swam in the lake. Turtles basked in the sun. Leaves rustled in the breeze while early horses darted between the trunks. We reveal more of the past with each fossil found.

Cockerellites liops is one of the more commonly found fishes in and around Fossil Butte National Monument.
NPS Photo

The red and purple layers of the Wasatch Formation sit below the ridgeline of Fossil Butte.
NPS Photo / John Collins

Only two fossil frogs have been found in the sediments remaining from Fossil Lake.
NPS Photo / Arvid Aase

The moon over a snow-covered Fossil Butte, the namesake of the park.
NPS Photo

Knightia eocaena is the most common fossil fish found in and around Fossil Butte National Monument.
NPS Photo / Arvid Aase

View of Fossil Butte from Cundick Ridge
NPS Photo

Echmatemys wyomingensis was a pond turtle that lived in ancient Fossil Lake.
NPS Photo

Fossil Butte with blue flax flowers in the foreground
NPS Photo / John Collins

Exhibit featuring fossils of stingrays, gars, paddlefish, and bowfins.

A variety of fossil fishes, insects, plants, reptiles, birds and mammals from Eocene Fossil Lake are displayed in the visitor center.

Building with overhanging roof and brick wall on either side. A butte is in the background.

The visitor center's hours change depending on the season.

A snow-covered porch with a snow-covered butte behind. The sky is bright blue with some clouds.

As you plan your visit, be sure to check out the current conditions at Fossil Butte National Monument.

A trail leading down amid sagebrush, aspen to the left, green hills out into the distance.

Experience the geology, wildlife, scenery, and wide open spaces of Fossil Butte by hiking the trails, dirt roads or taking the scenic drive.

A ranger standing in front of a butte holding two fossil fish.

In summer, we offer a variety of ranger programs including fossil preparation demonstrations and drop-in programs.

Tan stingray fossil facing right on pale cream stone.

From fishes, plants, mammals, and birds, discover the many fossils found in and around Fossil Butte National Monument.

A ranger holds a tablet in front of a diorama of a nearshore lake scene with animals.

Join us on a virtual field trip. Explore 52-million-year-old Fossil Lake from anywhere in the world.

Genealogy chart with a piece of volcanic tuff and a clock on top of it.

Teachers, have fun with these hands-on curriculum materials about Fossil Butte fossils designed for your classroom.

Fossil damselfly with white line a third of the way down dark brown wings.

Explore our photo galleries and videos highlighting fossils from the Green River Formation.

Last updated: July 10, 2026

Contact Info

Mailing Address:

P.O. Box 592
Kemmerer, WY 83101

Phone:

307 877-4455

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