BILLINGS, Mont. (AP) — Wildlife advocates have sued the federal government after it declined to designate some areas in the West as critical habitat for the imperiled Canada lynx.

Two coalitions of advocacy groups filed separate lawsuits over lynx on Monday in U.S. District Court in Missoula, Montana. They assert the U.S. Fish and Wildlife Service improperly excluded the southern Rocky Mountains of New Mexico and Colorado as protected habitat for the elusive, forest-dwelling wild cat.

The plaintiffs also say the agency left out important habitat in portions of Washington state, Idaho, Montana and Oregon. The lawsuit asks the court to strike down the September finding and send the issue back to federal wildlife officials for reconsideration. Lynx first gained federal protections in 2000. There is no reliable population estimate for the animals.