Subspecies
- Santa Cruz garter snake, T. a. atratus (Kennicott, 1860)
- Oregon garter snake, T. a. hydrophilus Fitch, 1936
- Diablo Range garter snake, T. a. zaxanthus Boundy, 1999
Read more about this topic: Aquatic Garter Snake
Subspecies
Read more about this topic: Aquatic Garter Snake