Species Profile

Quick Facts

  • The giant garter snake is the largest species of garter snake, ranging from 36 - 65 inches in length.
  • The giant garter snake is not dangerous to humans. It uses venom to help capture its prey, but that venom is harmless to people.
  • Giant garter snakes are dormant during the winter, when they hibernate in small mammal burrows or other crevices in the soil.
  • Giant garter snakes have developed a fast diving action that helps them escape from predators such as raccoons, skunks, opossums, and hawks.

The giant garter snake is listed as a threatened species under both the federal Endangered Species Act and California’s Endangered Species Act. Their population decline is largely due to the loss and fragmentation of their historic wetland habitat.


The giant garter snake is endemic to California’s Central Valley. Giant garter snakes are dormant in the winter and active from spring to mid-fall. During this hibernation period, they need dry habitat for burrows. When they are active, they use slow moving waterways with emergent vegetation for foraging and cover from predators, and they use the banks of waterways to bask in the sun.


Today only about 5 percent of their historical wetland habitat acreage remains, so many giant garter snakes live in the interconnected waterways associated with rice fields. Ricelands currently provide hundreds of thousands of acres of much needed habitat for the snakes.