(CNN) -- The gray wolf population in Wyoming has grown enough to be removed from the endangered species list and will stop receiving federal protection next month, the U.S. Fish and Wildlife Service announced Friday.
The decision means that gray wolf has recovered from near extinction throughout the Northern Rocky Mountains, which includes all of Idaho and Montana and parts of Washington, Oregon and Utah, officials said.
The wolves in Wyoming won't be protected under the Endangered Species Act effective September 30, when the packs will be managed by the state, federal officials said.
"The return of the wolf to the Northern Rocky Mountains is a major success story, and reflects the remarkable work of states, tribes, and our many partners to bring this iconic species back from the brink of extinction," Fish and Wildlife Service Director Dan Ashe said in a statement.
The Northern Rockies are home to at least 1,774 adult wolves and more than 109 breeding pairs, and the population has exceeded recovery goals for 10 consecutive years, officials said.
The vast majority of Wyoming's gray wolves live in the northwest section of the state, where the animals will be managed by state wardens as "trophy game" year-round, federal officials said.
Wyoming officials will regulate the timing, methods and numbers of gray wolves taken through regulated hunting. Wolves found to be preying on livestock also may be controlled, federal officials said.
Environmental and wildlife groups took exception to the federal decision, saying the gray wolf hasn't fully recovered.
"Today's decision by the Fish and Wildlife Service allows Wyoming to return to the days of random wolf killing that led to the species' endangerment in the first place," said Sylvia Fallon, wildlife conservation director at the Natural Resources Defense Council.
The environmental group Earthjustice said Congress last year gave hunters and trappers in Montana and Idaho the right to kill wolves that had been once protected, nullifying a court victory by the group that would have prevented the hunts.
"Wyoming's open season on wolves in almost all of the state would allow aerial gunning of wolves and even killing wolf pups in their den," Earthjustice attorney Jenny Harbine said.
"Wyoming law also allows unrestricted killing of wolves if they are found to be 'harassing' livestock or domestic animals, even if wolves are intentionally baited into the conflict," said Harbine. "These policies could drive wolves back into local extinction."
Last December, Wyoming counted 328 wolves, including 48 packs and 27 breeding pairs, the Wyoming Game & Fish Department said. That figure included 224 wolves, 36 packs and 19 breeding pairs outside Yellowstone National Park, state officials said.
In areas of Wyoming where wolves are designated as predatory, "no state license is required to take a wolf, and there are no closed seasons or bag limits," the state agency said. Hunters are required to report the kill to game wardens within 10 days and aren't required to present the skull or pelt, though state officials are encouraging them to do so for genetic monitoring.
Wyoming wildlife chief Brian Nesvik said, "We are taking a conservative approach to wolf hunting seasons during this time of transition from federal to state management. We need time to assume the important responsibilities of wolf population monitoring, sport harvest management and meeting Wyoming's commitments to wolf conservation in our state."
Wyoming officials must ensure population levels of at least 150 wolves and 15 breeding pairs, and the federal wildlife service will monitor the species in Wyoming, Montana and Idaho for at least five years to ensure the animal's recovery, officials said.
The federal agency can put the gray wolf back on the endangered list if necessary, U.S. officials said.
"Our primary goal, and that of the states, is to ensure that gray wolf populations in the Northern Rocky Mountains remain healthy, giving future generations of Americans the chance to hear its howl echo across the area," Ashe said. "No one, least of all Idaho, Montana and Wyoming, wants to see wolves back on the endangered species list. But that's what will happen if recovery targets are not sustained."
The gray wolf grows to 2.5 feet in height and up to 6 feet in length, weighing between 80 and 100 pounds. Its coat varies from black to white, and the animal is noted for its broad snout, round ears, and long, low howl.