A heat signal detected in a heavily forested part of Glacier National Park led rescuers to a 19-year-old boy who had slipped off a mountain trail and was missing, authorities said Tuesday.

Matthew Read, 19, had last been heard from on Friday and was reported missing on Sunday, the National Park Service said.

Missing hiker rescued in Glacier National Park, Mont., on May 8, 2023.
Matthew Lee. Glacier National Park

At 11 p.m. Monday, a helicopter detected Read’s heat signature in what was described as heavily wooded terrain. He was loaded into the helicopter and transferred to an ambulance, he said.

Read was stable, the park service said in a statement Tuesday.

He was hiking the Huckleberry Lookout Trail when he slid into a drain on Huckleberry Mountain in deep snow, the park service said.

«He descended into snow up to his chest, lost his phone, water bottle and shoes,» he said in a declaration. He couldn’t get back on the trail so he started down the trail, the park service said.

Glacier National Park covers about 1,583 rugged square miles in northwestern Montana.