CHOTEAU (AP) — Authorities say a U.S. Forest Service official has found a Pennsylvania man who had been missing in the Bob Marshall Wilderness since Monday.

Rocky Mountain District Ranger Mike Munoz said 21-year-old Eric Hellmuth was found alive on Friday.

Hellmuth was reportedly tired and dehydrated, but in good condition.

A backcountry outfitter reported that Hellmuth walked away from camp northwest of Augusta on Monday afternoon and hadn’t been seen since. Rescuers had to hike and ride horses 17 miles into the forest to reach the area where Hellmuth had gone missing.

The Bensalem, Pennsylvania resident was participating in a guide and packer school. He had last been seen wearing only a T-shirt, jeans and a pair of moccasins.

The search was being led by the Teton County Sheriff’s Office, which did not immediately have any information Friday afternoon. The sheriff’s office was assisted by Teton County Search and Rescue, the Lewis and Clark National Forest, Two Bear Air and the 40th Helicopter Squadron out of Malmstrom Air Force Base.