A coalition of conservation groups filed a lawsuit Thursday that challenges Forest Service road management strategies as being harmful to the threatened Cabinet-Yaak and Selkirk grizzly bear populations.

The lawsuit was filed in U.S. District Court in Missoula. The lawsuit seeks to invalidate road management strategies and standards that were adopted early this year by the Kootenai, Lolo and Idaho Panhandle national forests.

Joining in the lawsuit were the Cabinet Resource Group, Great Bear Foundation, the Idaho Conservation League, the Natural Resource Defense Council and the Selkirk Conservation Alliance.

The coalition contends that the forests are pursuing a strategy that will not go far enough in closing or obliterating forest roads to protect Cabinet-Yaak and Selkirk grizzly bear populations, each numbering an estimated 40 bears.

"Under the current situation, both the Cabinet-Yaak and Selkirk grizzly populations are warranted for endangered listing; both are suffering excessive mortalities; and both have populations too small to be viable," said Brian Peck of the Great Bear Foundation. "If we actually degrade the bears' habitat further, these populations haven't got a prayer."

Forest Service officials say the access management plans, which were approved as forest plan amendments, will make significant improvements in grizzly bear habitat security.

Roughly 540 miles of currently usable roads - some that are closed seasonally or year-round - will be converted to a "nondrivable status" in the next 10 years.

But that's not enough to put a dent in some 20,000 miles of forest roads that compromise grizzly bear habitat, the plaintiffs contend.