JACKSON, Wyo. >> Rangers caught a grizzly bear that they believe was involved in the first fatal bear attack in Yellowstone National Park since 2011, a park spokeswoman said.

The man’s body was found last Friday near Lake Village after he went hiking alone off-trail, without bear spray.

The National Park Service hasn’t released his name but says he was from Montana and was a five-year seasonal employee with a company contracted to operate medical clinics in the park.

Yellowstone spokeswoman Julena Campbell said that a trap set Friday caught an adult sow, but it didn’t catch any cubs the attacking bear is believed to have had with her.

The sow is being kept alive while tests are done to confirm it was involved in the attack.

If the bear was involved, it will be put down, Yellowstone Superintendent Dan Wenk said in a statement.

"We may not be able to conclusively determine the circumstances of this bear attack, but we will not risk public safety," Wenk said.

Campbell said the cubs, if captured, could be killed or adopted by a zoo or rehabilitation center.

The circumstances of the attack are unknown.

"It’s impossible for us to determine if it was a surprise encounter … or if it was more of what the biologists call a predatory attack," Campbell told the Jackson Hole News & Guide.

The attack occurred off-trail about a half-mile from the popular Elephant Back Loop Trail. The trail and surrounding area have been closed to the public until further notice.

Campbell said the man carried no pack or bear spray and did not disclose his plans to anyone.

Bruising around puncture wounds on the man’s forearms suggested he had tried to defend himself, Campbell said.