Nearly 600 square miles of federal, state and private land in northern Idaho and northeastern Washington is due to be designated critical habitat for dwindling woodland caribou.

Tuesday's announcement by the U.S. Fish and Wildlife Service came after environmental groups including the Center for Biological Diversity sued nearly a decade ago, contending the 1984 listing these North American reindeer cousins under the Endangered Species Act wasn't enough.

The rule forces federal agencies to ensure that anything they fund or authorize on land within the 375,562 acres of critical habitat won't result in the habitat's destruction.

Environmentalists say this new designation makes it tougher to create things like new groomed snowmobile routes, though Fish and Wildlife officials said they don't anticipate dramatic changes to the way they're currently managing the area.

Associated Press