DULUTH, Minn. (AP) - After three decades under the watchful eye of the federal government, the protection and management of wolves is falling back into the hands of the state and tribal governments.

At 12:01 a.m. today, the U.S. Fish and Wildlife Service officially removed the western Great Lakes population of gray wolves from the federal list of threatened and endangered species. Shooting wolves will no longer be a federal offense, although state laws already in place mean it will still be illegal in most cases.

The change comes about after a major rebound in the wolf population, particularly in Minnesota. Just 35 years ago, there were about 500 wolves estimated to roam northern Minnesota - the last timber wolves alive in the contiguous 48 states after they were shot, trapped and poisoned out of the rest of the country.

Today, there are an estimated 3,000 wolves in Minnesota and another 500 each in Wisconsin and Michigan.

The federal de-listing will make it easier for farmers, dog owners and government trappers to kill wolves. A farmer who sees a wolf threatening cattle can legally shoot it for the first time in 40 years.

Animal rights groups continue to question the federal government's action, with the Humane Society of the U.S. arguing that the lines drawn for the Great Lakes region are arbitrary and don't mean wolf populations have been fully restored to their former range.

"We believe it's a bad decision with many flaws," said John Lovvorn, vice president for litigation for the Humane Society. The group has filed a federal notice of intent to sue the Fish and Wildlife Service for the de-listing, although Lovvorn said no decision to sue has yet been made.

Lovvorn concedes that there is no longer the kind of anti-wolf sentiment that existed in the decades leading up to the animal's placement on the endangered list.

"It's been quiet" compared to disputes as recently as the late 1990s between landowners and the government over wolves, said Mike DonCarlos, wildlife research and policy manager for the Minnesota Department of Natural Resources.

Janet McNally, a livestock farmer near Hinckley, was a vocal critic of government wolf management in the late '90s, saying it didn't do enough to reduce wolf numbers in farm regions. She said the state takeover of the population is more a symbolic change than anything.