Macneill Lyons / AP file
An image provided by Yellowstone National Park, Mont., shows a gray wolf in the wild.
A small population of Mexican wolves in the Southwest would continue to receive federal protections, as a distinct subspecies of the gray wolf.
The document was first reported by the Los Angeles Times.
The U.S. Fish and Wildlife Service said Friday the rule was under internal review and would be subject to public comment before a final decision is made.
If the rule is enacted, it would transfer control of wolves to state wildlife agencies by removing them from the federal list of endangered species.
Wildlife advocates warn that could effectively halt the species' expansion, which has stirred a backlash from agricultural groups and some hunters upset by wolf attacks on livestock and big game herds such as elk.
Some biologists have argued wolves will continue spreading regardless of their legal status. The animals are prolific breeders, known to journey hundreds of miles in search of new territory. They were wiped out across most of the U.S. early last century following a government sponsored poisoning and trapping campaign.
In an emailed statement, the agency pointed to "robust" populations of the animals in the Northern Rockies and Great Lakes as evidence that gray wolf recovery "is one of the world's great conservation successes."
Wolves in those two areas lost protections under the Endangered Species Act over the last two years.
In some states where wolves have recovered, regulated hunting and trapping already has been used to drive down their populations, largely in response to wolf attacks on livestock and big game herds. The U.S. Fish and Wildlife Service recently reported that wolf numbers dropped significantly last year in Wyoming, Idaho and Montana for the first time since they were reintroduced in the mid-1990s.
Federal officials have said they are monitoring the states' actions, but see no immediate threat to their survival.
In Oregon and Washington, which have small but rapidly growing wolf populations, the animals have remained protected under state laws even after federal protections were lifted in portions of the two states.
Between 1991 and 2011, the federal government spent $102 million on gray wolf recovery programs and state agencies chipped in $15.6 million. Federal spending likely would drop if the proposal to lift protections goes through, while state spending would increase.
John Flesher reported from Traverse City, Mich.