SPOKANE, Wash. (AP) — Environmental groups plan to sue the U.S. Fish and Wildlife Service for failing to prevent the recent extinction of the last herd of mountain caribou in the Lower 48 states. The handful of remaining animals in the southern Selkirk Mountains herd were relocated into Canada last November, ending decades of efforts to save the herd.

The lawsuit blames the Fish and Wildlife Service for failing to designate protected habitat for the animals. The groups seek to establish protected caribou habitat as part of an effort to return the animals in the United States.