Grand Teton National Park officials closed Moose-Wilson Road on Friday after grizzly sow 610 was seen with cubs eating berries along the roadside, and one charged a car.

The closure comes after wildlife managers imposed stricter rules for wildlife viewing this summer, especially for grizzly bears. Park visitors must now stay at least 100 yards away from grizzly bears and wolves, even if people are in their vehicles.

Early Friday, “we had large numbers of visitors accumulating along the road taking pictures,” park spokeswoman Jenny Anzelmo-Sarles said. During that time, grizzly 610 “showed signs of agitation,” and a cub bluff-charged a park law enforcement vehicle.

“That could mean [the bear cub] is agitated with the number of people around,” Anzelmo-Sarles said. “It’s always a concern when there is aggressive behavior of bears against humans because it means that humans are in their space, and we’re too close. To prevent this kind of behavior, to prevent habituation of these bears, that’s one of the reasons we closed this road.”

The decision to close Moose-Wilson Road is to protect both the bears and park visitors, Anzelmo-Sarles said. The narrow, winding road and low visibility make it difficult to manage wildlife jams safely, she said.

Black bear jams along Moose-Wilson Road were a frequent occurrence last year, with park officials sometimes complaining that people got too close to the bruins.

Since then, park officials developed a management plan with “trigger points” to close the road during wildlife jams. One of those trigger points is grizzly activity along the roadside. Another is inadequate staff to manage wildlife jams. Anzelmo-Sarles said grizzly activity, not a staffing shortage, prompted Friday’s closure.

Some wildlife photographers have chafed against the new, stricter wildlife viewing rules, saying they’re unnecessary. People also expressed displeasure with Friday’s Moose-Wilson closure.

“We have gotten some feedback from folks in the area who were looking for an explanation for the closure,” Anzelmo-Sarles said. “Our chief ranger talked with them for a bit and hopefully appeased their concerns.”

Local wildlife photographer Tom Mangelsen — owner of the Images of Nature gallery in Jackson — showed up at Moose-Wilson Road right before the closure.

“There was about 25 people there, and it was the first time people had seen 610 for two or three weeks,” he said.

Mangelsen said the situation was “under control” when rangers closed the road. “It seemed like overkill to me, to say the least,” he said.

About eight wildlife watchers and photographers then went to the administrative offices at Moose hoping to talk to park superintendent Mary Gibson Scott.

“People were so upset that we went to talk to the superintendent to see if she could make some sense of this,” Mangelsen said.

Eventually, chief ranger Michael Nash came out to meet with the group, Mangelsen said.

“This is a sort of overreaction, basically,” he said. “It’s not very good for the Park Service image and not very good for what the parks are set up for.”

Similar closures are expected to continue throughout October.

“As we continue to see a greater presence of grizzly bears at the southern end of Grand Teton National Park, we anticipate this will not be the only time we do this,” Anzelmo-Sarles.

Mangelsen said the park’s elk reduction hunt is a bigger impact on bears and other wildlife than roadside photographers and wildlife viewers.

“It’s a double standard and it’s totally hypocritical,” Mangelsen said.