Fossil Butte National Monument Park
National monument protecting exceptionally preserved Eocene fossil beds
High-elevation fossil beds in Wyoming preserve Eocene fish, plants and insects; researchers and visitors come for museum exhibits, guided fossil talks and low-traffic hiking across sagebrush plateaus near the ancient Fossil Lake deposits.
Fossil Butte National Monument at a Glance#
Address: Fossil Butte National Monument, near Kemmerer, Wyoming, USA
Website: https://www.nps.gov/fobu
About 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.
Tips for Visiting Fossil Butte National Monument#
- Stop first at the visitor center to see the fossil displays and seasonal orientation talks - the center houses the best examples of Fossil Butte's famous fish and plants.
- Plan your visit for a weekday or earlier in the morning during summer to avoid busier hours; the monument is compact and can feel crowded at peak times.
- Remember that collecting fossils on-site is prohibited; enjoy the well-prepared specimens in the visitor center and on guided programs instead of searching in the field.
Best Time to Visit Fossil Butte National Monument#
Visit late spring through early autumn when roads, trails, and visitor services are most accessible and weather is milder.
Weather & Climate near Fossil Butte National Monument#
Fossil Butte National Monument's climate is classified as Cold Semi-Arid - Cold Semi-Arid climate with mild summers (peaking in July) and freezing winters (coldest in January). Temperatures range from -15°C to 27°C. Semi-arid with limited rainfall.
January
January is the coldest month with highs of -2°C and lows of -15°C. Light rainfall.
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February
February is freezing with highs of 0°C and lows of -15°C. The driest month with just 16 mm.
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March
March is freezing with highs of 4°C and lows of -10°C. Light rainfall.
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April
April is cold with highs of 10°C and lows of -5°C. Light rainfall.
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May
May is cold with highs of 16°C and lows of 0°C. The wettest month with 31 mm of rain.
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June
June is cool with highs of 21°C and lows of 4°C. Light rainfall.
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July
July is cool with highs of 27°C and lows of 6°C. Light rainfall.
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August
August is cool with highs of 26°C and lows of 6°C. Light rainfall.
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September
September is cool with highs of 20°C and lows of 1°C. Moderate rainfall (30 mm).
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October
October is cold with highs of 14°C and lows of -4°C. Light rainfall.
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November
November is freezing with highs of 4°C and lows of -10°C. Light rainfall.
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December
December is freezing with highs of -2°C and lows of -15°C. Light rainfall.