Hunters killed an adult male grizzly bear in Grand Teton National Park on Thanksgiving morning.

It was the first such killing tied to the park’s elk hunt, according to a park official.

Details are scant on the bear’s death, because it’s under investigation. But officials said the bear “reportedly charged the hunting party” around 7:30 a.m. along the east bank of the Snake River to the north of Schwabacher Landing. The hunters were 48-year-old David Trembly, a Dubois man, and Trembly’s 20- and 17-year-old sons, said Dwayne Trembly, the father of David Trembly.

Following the incident, Grand Teton officials discovered a cow elk carcass nearby and closed a half-square-mile area to the northwest of Teton Point Overlook.

“It was a large adult male, and it did not have any tags,” Grand Teton spokeswoman Jenny Anzelmo-Sarles said of the dead grizzly. “It is the first bear mortality within the park that was the result of a hunter.”

A team of park law enforcement rangers, biologists and management personnel is conducting the investigation. They will consult with the U.S. Fish and Wildlife Service because grizzly bears have Endangered Species Act protection, Anzelmo-Sarles said.

Grand Teton has not said if members of the hunting party carried or used bear spray.

Dwayne Trembly, of Cheyenne, wouldn’t comment in detail because of the investigation, but he said in a phone interview Friday that the run-in was “pretty traumatic” for his son and grandsons. None of the hunters was injured.

Trembly described the group as “pretty experienced hunters.” He said they’ve taken part in Grand Teton’s hunt — officially called the “elk reduction program” — since 2010.

The party was back elk hunting Friday, “still trying to find one,” Trembly said.

“We’re not going to go back to the river bottom,” he added, referring to the area where the grizzly shooting took place.

Anzelmo-Sarles said there have been no recent reports of other bears along the Snake River bottoms inside the park. In the course of Thanksgiving Day, however, observers at the Teton Point Overlook saw four other grizzly bears on the west bank of the Snake.

Wildlife photographer Tom Mangelsen was on the scene shortly after hearing that a grizzly had been killed. There were 40 or 50 hunters, outfitters, photographers and residents gathered at Teton Point overlook while Park Service officials worked to remove the bruin, Mangelsen said.

“We saw 610 and her three cubs yesterday mid-morning when everybody was down there trying to sort out what happened,” Mangelsen said.

Mangelsen is a longtime critic of the park’s elk hunt.

“I came from a very long and strong hunting background, but this is not a hunt,” Mangelsen said. “It increases bad behavior. People are chasing elk in their vehicles while on their cellphones. They’re herd shooting.”

As of Friday, Grand Teton had issued one citation and another six warnings to hunters taking part in the elk hunt, Anzelmo-Sarles said. Hunter violations ranged from shooting from roads to not having permits on them to not carrying bear spray, which is required in the park, she said.

“I heard yesterday from a hunter that he was following the blood trail of an injured elk and he had a bear come up behind him,” Mangelsen said Friday. “This was three days ago.”

Tim Mayo, a Jackson real estate agent and fervent critic of the park hunt, called for Grand Teton officials to act swiftly. On Oct. 24, park officials issued an area closure also just north of Schwabacher Landing after an elk hunter returned to find four grizzly bears eating his downed cow.

“At this point, the superintendent should unequivocally close the river bottom to the hunt,” Mayo said. “It’s not safe.”

The shooting marks the year’s 51st known or probable grizzly death in the Greater Yellowstone Ecosystem, according to the Northern Rocky Mountain Science Center. About a third of them are usually related to hunting, a Grand Teton statement said.