Valley Garter Snake

A snake is barely visible in dead vegetation

The valley garter snake is one of six reptile species and the largest species found in the park.


Scientific Name

Thamnophis sirtalis fitchi


  • Subspecies of the common garter snake.
  • Medium sized snake up to 34 inches long.
  • Nearly black background color with three bright stripes running the length of the body; underside is pale yellow or bluish gray.
  • Most distinguishing characteristics of this subspecies in our region are the irregular red spots along the sides.


  • Thought to be common in the past, now in decline for no apparent reason.
  • Closely associated with permanent surface water.
  • In Yellowstone area, observed only in the Falls River drainage in the Bechler region and three miles south of the south entrance along the Snake River.


  • Generally active during the day.
  • In the Yellowstone area, it eats mostly toads, chorus frogs, fish remains, and earthworms; can eat relatively poisonous species.
  • Predators include fish, birds, and carnivorous mammals.

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