Environmental groups want to stop sheep grazing on public lands in the region. The issue is playing out in the courts in Idaho and Montana.
The plaintiffs want to eliminate the grazing in part because domestic sheep can make wild sheep sick--with diseases like pneumonia.
Chase Adams is with the American Sheep Industry Association. He’s skeptical. "That pathogen has been found to be endemic in bighorn herds across the west ... So that really calls into question the current analysis around complete and utter separation."
But disease transmission isn’t the only concern for wildlife advocates.
Greta Anderson is with Western Watersheds Project. She says introducing domestic animals puts native predators at risk--like grizzly bears and wolves. When they prey on livestock, sometimes managers decide to remove or kill the predators.
"And then the native predator species are removed lethally in order to 'manage' them," says Anderson.
The latest disputes over domestic sheep grazing are playing out in the courts for the Gravelly Range in Montana and the Caribou-Targhee National Forest in Idaho.