The South Selkirk mountain caribou herd may be extinct after aerial surveys found only three remaining animals.

“The Selkirk mountains are still going to be a big wild cool place, but we have lost something, some piece of that system,” said Bart George, a wildlife biologist for the Kalispel Tribe. “They’re an animal that’s been there for 70,000 years. It’s a big deal.”

Kalilspel Tribal biologists conducted two aerial surveys in March, finding only three female caribou. Last year there were about a dozen of the endangered animals. The three female caribou spotted were collared.

Less than 10 years ago there were about 50 animals in the herd.

It is still possible that there are more caribou, George said. Biologists hope the collared animals will lead them to other animals missed during the survey.

“It’s not out of the question that we missed some,” George said.

But even if true, it’s a precarious position for a struggling species.

The mountain caribou have struggled as old growth forests have been thinned by logging and other industrial activities, George said. With thinner forests the caribou have become more susceptible to predation.

Thinned forests have led to other problems, including vehicle strikes on Highway 3 in British Columbia.

“The biggest part is the habitat changes up there from industrial logging and development,” George said.

It’s not known what happened to the herd between last year and March.

“It’s anybody’s guess what happened,” he said. “A lot of people are wanting to point there fingers at a lot of different things … it could be an avalanche that took out the group.”

The South Selkirk caribou herd was the only one living in both the United States and Canada. It ranges through the high country along the crest of the Selkirks near the international border. The remaining 14 or so herds are all in Canada. It’s estimated that fewer than 1,400 mountain caribou are left in North America.

As the biologist collared the three animals, they took blood samples. Those samples will be tested to see if the caribou are pregnant, George said. The test results should be back in about a week.

“If they come back pregnant, we’ll have a little bit of hope,” he said.

If the three caribou are the only remaining ones and aren’t pregnant, George said it’s possible they will be relocated and introduced into a different herd.

“We’re going to try and bring them back, no matter what, as long as there is any glimmer of hope,” he said.

What makes the possible extinction more devastating for George is that it wasn’t a surprise. Other herds in the range have “blinked out” in recent years. Full-scale recovery efforts only started recently, with Canada starting to control its wolf population in 2014, and maternal pen projects and population augmentation efforts only starting a year ago.

Canadian wildlife agencies removed about 20 wolves over four years to reduce the predator impact on the South Selkirk caribou.

The U.S. Fish and Wildlife Service wrote its first recovery plan for mountain caribou in the early 1980s and it was reworked in 1994. Working with Canadian agencies and First Nations, caribou from other regions were trapped and released in the area with some positive results.

Although cougars and bears kill caribou, wolves have had the biggest impact on the animals.

“I’m mourning for these animals,” George said. “They mean a lot for me. I’m going to have a hard time looking at the Selkirk Range the same.”