A man kills a grizzly bear in Montana after it attacks while he is picking berries

FILE - This undated file photo provided by the Montana Fish, Wildlife and Parks shows a sow grizzly bear spotted near Camas, in northwestern Montana. (Montana Fish, Wildlife and Parks via AP, File)

A 72-year-old man picking huckleberries in Montana shot and killed a grizzly bear after it attacked in a surprise encounter and injured him badly enough that he had to be hospitalized, authorities said Friday.

The man was alone on national forest land when the adult female charged him Thursday. He suffered significant injuries before killing the bear with a handgun, Montana Fish, Wildlife & Parks officials said.

The bear was likely reacting defensively to protect cubs, agency spokesperson Dillon Tabish said.

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Wildlife workers set out game cameras in the area to try to confirm the presence of any cubs. If cubs are found, it's uncertain if they would be captured because it is difficult to find facilities qualified to take them, he said.

"Depending on the age, we might leave them in the wild because they have a better chance of survival, rather than have to euthanize them," Tabish said.

The attack happened on the Flathead National Forest about two miles (3.2 kilometres) north of Columbia Falls, a northwestern Montana city of about 5,500 people, according to the state wildlife agency.

The victim's name and further details on his condition were not released.

Meanwhile, Fish, Wildlife & Parks staff shot and killed an adult female grizzly Thursday after it had become accustomed to seeking out food from people and breaking into houses in and around Gardiner, a town of about 800 people just north of Yellowstone National Park.

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Pet food, garbage and barbeque grills left outside and accessible to bears contributed to the problem, according to a department statement. No people were hurt by the bear before it was shot in the Yellowstone River.

Wildlife managers sometimes capture and move grizzly bears that are known to cause problems for people. But they will kill ones involved in predatory attacks on people or if they are deemed likely to keep causing problems regardless of being moved.

The Gardiner-area grizzly was killed about 300 miles (500 kilometres) south of the unrelated attack in the Columbia Falls area. An estimated 2,000 grizzlies roam western Wyoming, eastern Idaho, western Montana, while several thousand more inhabit the Canadian Rockies and Alaska.

Grizzly bears in the contiguous U.S. are listed as threatened under the Endangered Species Act. Elected officials in Rocky Mountain states are pressing federal officials to lift their protected status, which could open the door to future hunting.