A patterned snake with it's tongue out
Reptiles are not well studied in Yellowstone National Park. The bullsnake (shown here) is one of six, and the largest, reptile species found in the park.

NPS/Jane Olson


Yellowstone provides a valuable area for the study of reptiles. Information about the status and trends of reptiles here may shed light on declines documented in other high-elevation protected areas of the western United States. Many reptiles congregate to breed or overwinter, and they can be adversely affected by disturbance or loss of key sites.



Koch, E.D. and C.R. Peterson. 1995. Amphibians & reptiles of Yellowstone and Grand Teton national parks. Salt Lake City: Univ. of Utah Press.

Parker, J. and S. Anderson. 2001. Identification guide to the herptiles of Wyoming. Cheyenne, WY: Wyoming Game and Fish Department.

Patla, D.A. and C.R. Peterson. 1999. Are amphibians declining in Yellowstone National Park? Yellowstone Science. 7(1): 2–11.

Stebbins, R.C. 2003. A field guide to Western reptiles and amphibians. 3rd edition. Boston: Houghton-Mifflin Co.

A tan and black snake on a rocky surface

Bullsnakes are often mistaken for rattlesnakes because of their appearance and behavior.

A tan and brown spotted snake with rattler in a coil
Prairie Rattlesnake

Prairie rattlesnakes are the only dangerously venomous snakes in Yellowstone.

A brown snake on gravel next to a human hand
Rubber Boa

Rubber boas are usually found in rocky areas near streams or rivers with nearby shrubs or trees.

A dark gray, tan, and white striped lizard with small spikes on gravel
Sagebrush Lizard

The sagebrush lizard is the only lizard in Yellowstone.

A black, white & red snake on a rock surface
Common Gartersnake

Common gartersnakes are only found in southern parts of the park.

A white and tan striped snake with black dots on a rock
Terrestrial Gartersnake

Terrestrial gartersnakes are the most common reptile in Yellowstone.

A young bison calf with rust-red fur.

Learn about the park's abundant and diverse species—67 mammals, 330 birds, 16 fish, 5 amphibians, and 6 reptiles.


Last updated: February 1, 2021

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Yellowstone National Park, WY 82190-0168



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