Updated

Ranchers in Minnesota, Michigan and Wisconsin are howling with anger about a wolf population that has skyrocketed to over 400 gray wolves (search) in their region.

The species has been federally protected for over 30 years, but now the gray wolf is back in much bigger numbers. Wisconsin ranchers are particularly wary of the wolves because the animals are preying on livestock.

"We're at a point now where we would like to authorize landowners to be able to shoot wolves that are attacking livestock. And because they are still listed as a federally endangered species ... we don't have that authority," said Adrian Wydeven, a conservation biologist for the Wisconsin Dept. of Natural Resources (search).

The Fish and Wildlife Service tried to solve the problem by taking the gray wolf off the endangered species list, but it was sued by environmental groups like the Sierra Club (search).

In a victory for environmentalists, a federal judge in Oregon ruled against the de-listing of the wolves.

"It's true they are doing very well in Wisconsin and Michigan and Minnesota ... but we need success in these core areas so they can distribute and re-populate some of the surrounding states where wolves aren't doing so well," said Collette Adkins Giese, a member of the Sierra Club's North Star Chapter legal committee.

Click in the box near the top of the story to watch a report by FOX News' Steve Brown.