Once considered plains animals — they lived as far east as the Dakotas, as far south as Texas, and Lewis and Clark encountered them across the prairie — grizzlies were routinely killed by settlers as a threat to livestock and driven into the mountains, their last redoubt. After more than three decades of recovery efforts, though, they are coming down from their refuge and greatly expanding their range. “Bears are recolonizing their grassland habitat,” said a pleased Mr. Talmo. “They are showing up in places where they haven’t been seen in generations.”

Last year a grizzly bear killed chickens near Loma, Mont., a farming community 175 miles from the mountains, the farthest east a grizzly is known to have traveled in the last century. People there were shocked. It was the bear’s second offense, and it was tracked down, trapped and euthanized. In May, a rancher near Fairfield, Mont., a town also on the plains, shot two grizzlies that had killed seven of his sheep. Shooting an endangered species, unless in defense of a human life, is illegal, and he was fined $2,000 in federal court.

Thirty-six years ago, when the grizzly was first listed as threatened, there were no bears along the Rocky Mountain Front, the plains at the base of the Rockies. If one was spied, it was routinely killed by ranchers. Now there are over a hundred, perhaps many more.

Because of the growth of the grizzly population, United States Fish and Wildlife Service officials are writing a plan to manage the bear if its protected status as threatened, under the Endangered Species Act, is lifted. Such a change is probably at least a few years away. Still, said Christopher Servheen, the service’s grizzly bear recovery coordinator since 1981, “they’re recovered, they’re doing well, they are pushing out in all directions.”

Some here think removing federal protections is overdue, and would welcome it. “You’ll be able to protect your property again” by shooting bears, said Bert Guthrie, a retired sheep rancher. “That’s a good thing.”