BILLINGS, Mont. (AP) - The Obama administration on Wednesday moved to lift Endangered Species Act protections for 5,500 gray wolves in the Northern Rockies and Great Lakes, drawing the line on the predators' rapid expansion over the last two decades.

Public hunts for hundreds of wolves already are planned this fall in Idaho and Montana.

Conservationists have hailed the animal's recovery from near extinction last century as a landmark achievement - one that should be extended to the Pacific Northwest and New England.

But their return has stirred a backlash from agriculture and sporting groups angry over wolf attacks on livestock and big game herds.

Interior Department officials said Wednesday that the most suitable wolf habitat already was occupied. No further introductions of the species are planned.

Many biologists say wolves recovered to sustainable levels a decade ago in some parts of the lower 48 states. But it took a rider to the federal budget bill inserted by Western lawmakers to overcome years of lawsuits and lift protections for 1,300 wolves in the Northern Rockies.

The rider barred any courtroom challenges and marked the first time Congress has removed an animal listed under the endangered act. Protections for the Rockies wolves are to be lifted effective with a Thursday notice in the Federal Register.

About 4,200 wolves listed as threatened in the western Great Lakes also are slated to lose protections. That could happen by the end of this year, following the review of public comments received on the proposal over the next two months.

"From a biological perspective, gray wolves have recovered," said Interior Secretary Ken Salazar. "That is a remarkable milestone for an iconic American species."

The Great Lakes proposal also includes portions of North and South Dakota, Iowa, Illinois, Indiana and Ohio, although government biologist Laura Ragan said no wolves permanently reside in those states.

A pending petition before the Interior Department seeks to extend the government's wolf recovery plan nationwide. But Noah Greenwald with the Center for Biological Diversity, the sponsor of the petition, said Wednesday's announcement made clear that the government has no such intentions.

"In our view wolf recovery is not done," Greenwald said. "We're disappointed with seeing the Fish and Wildlife Service attempt to get out from under it."

Fish and Wildlife officials said they plan to review the gray wolf's status in the Pacific Northwest and the desert Southwest.

Gray wolves also are coming off the list in eastern states, but officials say that's because emerging science indicates that another predator, the Eastern wolf, is the region's native wolf species. Those are now largely absent from the United States but occasionally wander from Canada into New England.