Six environmental groups have filed a legal motion to intervene in a lawsuit by snowmobilers challenging the federal government’s designation of land in Idaho, Montana, Washington, Wyoming, Maine and Minnesota as critical habitat for Canada lynx, the Associated Press reports. The Wyoming State Snowmobilers Association and Washington State Snowmobile Association sued after the U.S. Fish and Wildlife Service designated 39,000 square miles as critical habitat for the lynx, up from the 1,850 square miles previously designated.