The grizzly sow known as 610 moved off the south end of Grand Teton National Park last week, forcing officials to haze the bruin and her three cubs back to the preserve.

Bear 610, the daughter of bear 399, foraged hawthorn berries and bluff-charged vehicles on the Moose-Wilson Road last week, prompting closure of the road, before she left the park. The grizzly mother’s movements are a departure from usual patterns and could be due to sparse natural forage from the dry, hot summer, officials said.

“It’s only speculation, but it’s somewhat likely that the reason that she made that movement is because of food,” said Steve Cain, Grand Teton’s senior wildlife biologist. “There isn’t a lot on the landscape to eat and she’s in search of food.”

Mike Boyce, a bear management specialist with the Wyoming Department of Game and Fish, was in charge of hazing 610 back to Grand Teton. The bears and cubs were on private land less than a mile from the park’s southern border Thursday when he responded to reports.

Boyce used “cracker shells,” a flying firecracker of sorts, to urge 610 back into the park, a safe haven for a bear that’s accustomed to being around people.

“We really feel that the residential areas around Grand Teton National Park are just not a suitable place to have a highly human-habituated female grizzly and her three cubs,” Boyce said.

Cain voiced the same opinion.

“If she leaves to an area where there’s developments, it’s just a problem that’s waiting to happen,” he said.

Boyce agreed 610 probably left the park for food.

“Her body condition looked poor to me,” Boyce said. “She looked thin. The natural foods are in poor condition right now.”

Having cubs likely contributed to her being thin.

“But I think that’s normal for a female grizzly bear with three cubs in a poor food year,” he said.

The bear specialist added that 610’s cubs were “big and robust.”

There’s some uncertainty over what food drew 610 out of the park.

Tom Mangelsen, a wildlife photographer who has followed 610 and her cubs regularly in recent years, theorizes that the grizzly mother was drawn by an elk hunt on nearby private land. The photographer had not seen the bear in the past week.

Game and Fish’s elk season on private land from Wilson north to Grand Teton opened Aug. 15, the day before 610 left the park.

“She hears the gunshots, and she’s used to it,” Mangelesen said. “They learn that this is a dinner bell. They get accustomed to it. That’s not a good thing.”

Boyce said he saw nothing that indicated 610 was being attracted to gut piles left by hunters.

“She was on the move when I saw her — she wasn’t feeding,” he said. “I don’t believe that there’s a lot of hunting activity going on there right now. ... There just aren’t that many gut piles on the ground.”

Grand Teton has heard no reports that have confirmed bear 610’s whereabouts since Saturday, Cain said. Mangelsen said Tuesday he heard through co-workers that the grizzly mother was wandering Antelope Flats near the Teton Science Schools building.

Grand Teton and Game and Fish will work together if 610 wanders back onto private lands that aren’t suitable for grizzlies, Boyce said.

Both hazing and relocation to the north end of the park — if it’s a continued problem — are on the table, he said. Bear 610 has never been relocated, but has been captured for research.