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.


Number in Yellowstone

They are less studied than amphibians in Yellowstone. There are 6 confirmed species:

  • Bullsnake
  • Prairie rattlesnake
  • Rubber boa
  • Sagebrush lizard
  • Common gartersnake
  • Terrestrial gartersnake


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

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.



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.

Last updated: June 14, 2017

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Mailing Address:

PO Box 168
Yellowstone National Park, WY 82190-0168



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