Yellowstone provides a valuable study area; 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.

A tan and black snake on a rocky surface

Bull Snake

Bull snakes 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 and white snake on dead grass

Valley Garter Snake

Valley garter snakes are a subspecies of the common garter snake.

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

Wandering Garter Snake

Wandering garter snakes are the most common reptile in Yellowstone.


Quick Facts

Number in Yellowstone

Six species: bull snake, prairie rattlesnake, rubber boa, sagebrush lizard, valley garter snake, and wandering garter snake. They are less studied than amphibians in Yellowstone.


  • None of the park’s reptiles are federally listed as threatened or endangered.
  • Researchers began inventorying reptiles and amphibians in 2000.

More Information


The Yellowstone Resources and Issues Handbook, updated annually, is the book our rangers use to answer many basic park questions.

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.

Contact the Park

Mailing Address:

P.O. Box 168
Yellowstone National Park, WY 82190-0168


(307) 344-7381

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