The U.S. Fish and Wildlife Service's critical habitat designation announced Tuesday is a response to a 2005 lawsuit.
Environmentalists claimed in the suit the Sierra Nevada bighorn sheep was threatened with extinction because its habitat wasn't protected under the Endangered Species Act.
The new critical habitat area is in the eastern Sierra Nevada, where the wild bighorns forage for sagebrush and grasses growing near granite peaks.
The Fish and Wildlife Service will now analyze whether grazing domestic sheep or allowing offroad vehicles nearby could jeopardize the bighorns' recovery.
