Reptiles
Western Terrestrial Garter Snake
Thamnophis elegans · also called wandering garter snake
Above the treeline in a western mountain meadow still patched with late-summer snow, a western terrestrial garter snake moves easily across ground most other North American snakes would find unbearably cold, entirely at home at an elevation few reptiles ever bother reaching.
Overview
The western terrestrial garter snake, Thamnophis elegans, is a highly adaptable snake native to a broad range of habitats across western North America, from British Columbia south through much of the western United States. Its exceptional elevational tolerance and reduced dependence on water set it apart from many of its more water-bound garter snake relatives.
A garter snake that climbs higher than the rest
While most garter snakes stay close to lowland water, the western terrestrial garter snake has pushed its range upward into genuinely mountainous terrain, tolerating cold and elevation that would keep most other North American snakes firmly at lower ground.
Status
Least Concern — widespread and stable across suitable habitat throughout western North America.
Western Terrestrial Garter Snake: common questions
How high in elevation can the western terrestrial garter snake be found?
A western terrestrial garter snake ranges to higher elevations than almost any other North American snake species, found active in mountain habitat where snow can still linger well into summer, an unusual cold tolerance compared with most reptiles, which typically avoid such high, cool environments.
Why does this garter snake's appearance vary so much?
The western terrestrial garter snake displays considerable variation in colour and stripe pattern across different populations spread across its broad range, from bold striping in some areas to more checkered or blotched forms elsewhere, reflecting local adaptation across the many different habitats the species occupies.
Does the western terrestrial garter snake need to stay near water?
Not as much as many other garter snake species — a western terrestrial garter snake is more terrestrial and comfortably ranges well away from ponds and streams, unlike more water-dependent relatives that rarely stray far from a reliable water source.
Where does the western terrestrial garter snake live?
The western terrestrial garter snake is native to a broad range of habitats, from wetlands to mountain meadows, across western North America, extending from British Columbia south through much of the western United States.