The giant garter snake is one of North America's largest native snakes, reaching up to 64 inches in length and endemic to California's Central Valley, where it originally inhabited natural wetlands. Unfortunately, wetland destruction for agricultural, urban, and industrial development has eliminated more than 90 percent of suitable habitat for the species, forcing snakes to rely heavily on rice fields and managed marsh areas.

The giant garter snake could be left high and dry by proposed water transfers and the rapid conversion of rice fields and associated wetlands habitats to dryland farming. Accordingly, the Center is making sure that comprehensive surveys for garter snakes are conducted before water transfers are approved, and we've warned federal agencies that they must properly evaluate the impacts, limit the allowable “take” (harming or killing) of these rare snakes, and ensure that suitable habitat creation and mitigation measures take place before large-scale changes occur in rice farming that could eliminate remaining garter snake habitat.

Heavy use of toxic pesticides in the Central Valley is also a contributing factor in the decline of this once-abundant garter snake. Center reports in 2004 and 2006 detailed the risk pesticides pose to the giant garter snake and the Environmental Protection Agency's failure to regulate pesticides harmful to endangered species. We continue to monitor and oppose harmful chemical pesticide use in California through our Pesticides Reduction Campaign.