Two rare garter snakes found in New Mexico and Arizona have been added to the federal list of threatened species.
The U.S. Fish and Wildlife Service has finalized protections for the narrow-headed garter snake and northern Mexican garter snake.
Biologists say the snakes are threatened by exotic species and the loss of river and streamside habitats.
Environmentalists have been pushing for the snakes to be listed for more than a decade. They say the reptiles have undergone dramatic declines and are now limited to small, isolated populations.
Federal biologists say there are only five northern Mexican garter snake populations in the U.S. that are considered viable, and all are in Arizona.
There are populations of narrow-headed garter snakes in a handful of spots in Arizona and New Mexico.