indicates the Yellowstone bear population has grown from as few as 136 in 1975 to an estimated 700, the U.S. Fish and Wildlife Service said in a statement Thursday.
"Stable population numbers for grizzlies for more than a decade also indicate that the Yellowstone ecosystem is at or near its carrying capacity for the bears," it said.
"In response to the successful recovery of one of the nation's most iconic animals, the U.S. Fish and Wildlife Service today proposed to remove the grizzly bear in the Greater Yellowstone Ecosystem from the Federal Lists of Endangered and Threatened Wildlife
," it said.
Delisting means the bears are no longer threatened, and would not be protected by the Endangered Species Act.
They could be hunted within the Greater Yellowstone Ecosystem, which lies in Wyoming, Idaho and Montana
, though not the Yellowstone National Park itself.
The wildlife service said the restoration of bear populations in Montana, Wyoming and Idaho "stands as one of America's great conservation successes."
"Our proposal today underscores and celebrates more than 30 years of collaboration with our trusted federal, state and tribal partners to address the unique habitat challenges of grizzlies," director Dan Ashe said.
"The final post-delisting management plans by these partners will ensure healthy grizzly populations persist across the Yellowstone ecosystem long into the future."
Public chance to comment
The wildlife service is seeking comment from the public, agencies and scientists after publication in the Federal Register,
expected in the next few days.
"Even with this proposed delisting, the service remains committed to the conservation of the Yellowstone grizzly bear, and will stay engaged to ensure that this incredible species remains recovered," Ashe said.
Still in need of protection?
However, the National Resources Defense Council
questioned the proposed move.
"Yellowstone grizzly bears are an isolated population that is experiencing high levels of conflicts with people and is likely declining in the wake of the loss of whitebark pine, a critically important food source," said Sylvia Fallon
, a senior scientist at NRDC.
Fallon questioned the accuracy of the population estimates, saying the bears were on the decline.
She added they would likely also need to be connected to bears outside the Greater Yellowstone Ecosystem to avoid genetic problems.
"The Endangered Species Act has been tremendously successful at saving this population and preventing its demise," she said.
" And retaining those valuable protections until the Yellowstone grizzly population is more robust and its future more certain is the best way to turn that past success into true recovery."
The Fish and Wildlife Service removed the Yellowstone grizzly bear population from the threatened species list in 2007, but the decision was challenged and later overturned by a federal district judge. A later appeal by the service failed.
The wildlife service describes endangered species as those at the brink of extinction now
while a threatened species "are likely to be at the brink in the near future."
Awake and hungry
Meanwhile, Yellowstone National Park has warned that its grizzlies are awake, hungry and looking for food.
The National Parks Service said the first confirmed report of grizzly bear activity after the winter hibernation came nearly two weeks ago.
"Bears begin looking for food soon after they emerge from their dens," the parks service said in a statement.
It recommended that park visitors stay in groups of at least three, make noise on the trail and carry bear spray.
"Yellowstone regulations require visitors to stay 100 yards from black and grizzly bears at all times.
The best defense is to stay a safe distance from bears and use binoculars, a telescope or telephoto lens to get a closer look," the parks service said.
Yellowstone closes areas of the park
where humans are more likely to encounter bears that could react aggressively while feeding on elk and bison carcasses.