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Reptiles of Washington

Western terrestrial garter snake
(Thamnophis elegans)


What they look like

  • Western terrestrial garter snakes are medium-sized snakes with an average length of 38 inches (for the Washington subspecies).
  • They are highly variable in pattern and coloration, so not all individuals will match the following descriptions.
  • Most of these snakes are grey to brown and have three long stripes along the length of their body that are either yellow or cream in color. Small dark spots form along these stripes. Their underside is mostly grey. 

Where they live

  • Western terrestrial garter snakes are found in southwestern Canada and western United States.
  • Despite the “terrestrial” part of their name, these snakes spend most of their time living near the water’s edge along ponds, lakes, wetlands, streams, rivers, and irrigation canals.
  • Can also be found in other habitats ranging from coniferous forests to desert riparian areas.

What they eat

  • Western terrestrial garter snakes can eat a very wide range of animals, including slugs, worms, snails, leeches, tadpoles, frogs, mice, fish, lizards, small birds, and even others of their own species.


  • Between late July and early August, females give live birth to 8 to 12 young.

Cool Biology Facts

  • To help defend themselves, western terrestrial garter snakes will secrete and smear substances from their scent glands all over themselves and their predator.
  • Western terrestrial garter snakes are so variable in color that even all black individuals have been seen!


Distribution Map


Western terrestrial garter snakes are considered “least concern” due to their wide-spread range, no known major threats, large population sizes, and abundant populations.