Sierra Garter Snake

The Sierra garter snake (Thamnophis couchii) is a non-venomous, semi-aquatic snake native to the Sierra Nevada and surrounding regions of California and western Nevada. It typically grows between 18 and 40 inches in length with a slender body featuring dark coloration and light longitudinal stripes, often with a checkered pattern. Highly adapted to aquatic environments, this species is commonly found near rivers, streams, and mountain lakes, where it is an agile swimmer and effective predator of fish, amphibians, and invertebrates, which it captures with quick strikes. Unlike some garter snakes, it does not rely on constriction but subdues prey with mild venom that is harmless to humans. Sierra gartersnakes give birth to live young, with litters ranging from 10 to 25 offspring. They are active during the day, often basking on rocks near water sources. When threatened, they may release a foul-smelling musk as a defense mechanism. Though not considered endangered, Sierra garter snake populations are affected by habitat degradation, pollution, and competition from invasive species. Their presence in healthy aquatic ecosystems makes them important indicators of environmental quality.

Fun fact: While classified as non-venomous, the sierra garter snake actually produces an extremely mild venom which is lethal to its prey but has never harmed a human.