Gray wolves, whose packs now prowl through the northern Rockies and the forests along the Great Lakes, no longer need endangered-species protection to prevent their extinction, the Obama administration said Friday.

The Fish and Wildlife Service unveiled a proposal to eliminate the remaining restrictions across the country, saying wolves are flourishing again. The only populations to have protection, under the proposal, would be Mexican wolves in southern Arizona and New Mexico and a small experimental population in North Carolina.

The announcement by Daniel M. Ashe, the director of the Fish and Wildlife Service, marked the imminent end of 50 years of controversial efforts to bring back a predator that once roamed the continent but had been all but exterminated in the United States by the mid-20th century.

“Wolves are recovered and they are now in good hands,” Mr. Ashe told reporters on a conference call. “States are the most competent people to make the decisions in the future about how many wolves” there should be and “where wolves can add value to the landscape in the years ahead,” he said.