Hunted to near extinction in the U.S. Rocky Mountain territory, grizzlies were declared an endangered species in 1975 throughout the western states and given special protection.
After 30 years, the population in Yellowstone — which straddles the states of Idaho, Montana and Wyoming — has risen from about 200 in 1982 to more than 600 today, say government and park experts.
"The Greater Yellowstone's population of grizzlies, a population that once was plummeting toward extinction, has now recovered," said Interior Secretary Gale Norton.
"These bears are no longer in danger," Norton told a press conference.
Often described as fearless, grizzlies are among the world's largest land predators, second in size only to Kodiak bears — a brown bear subspecies that lives in Alaska — and polar bears.
Since the recovery of the Yellowstone population, there have been more sightings and confrontations with the animals outside the park's borders, where hunting of other wildlife is permitted.
Normally feeding on elk calves in breeding season, the bears are now so accustomed to feasting on "gut piles," the remains of prey left by hunters that the beasts now react to rifle shots as though they were dinner bells, hunters said.
