An autistic man has been rescued from Utah's remote Escalante Desert after surviving at least three weeks alone in temperatures that topped 37.8 Celsius by eating roots and frogs.
William Martin LaFever, 28, was found emaciated and unable to walk on Thursday, more than a month after he was last heard from. He was spotted by a police helicopter, sitting in the Escalante River and waving weakly.
LaFever's father told police that his son, who is autistic, had called him on June 6 or 7 to say he had hitchhiked with his dog to Boulder, Utah, to go hiking, but had run out of money and some of his gear had been stolen.
The father, John LaFever, promised to wire some money to Page, Arizona, about 112 km away cross-country, but William did not call back and appeared to have tried to make the journey largely on foot.
LaFever, who is from Colorado, told rescuers his dog had run away, he had run out of food and all he had left were his clothes and shoes. He dug up roots and caught river frogs for food.
He was thought to have hiked about 80 km in searing heat through 91m deep canyons and across some of Utah's most remote landscapes, said Garfield County sheriff's spokeswoman Becki Bronson.
The area is commonly used by wilderness schools to teach survival skills, and temperatures have risen higher than 37.8 Celsius in recent days.
Authorities said they do not know exactly how long LaFever was stranded in the desert, but that it was at least three weeks. Family members reported him missing on Monday, about a month after he last spoke to his father.
Rescuers say he is lucky to be alive.
"People from all over the world come to hike this area because it's a challenge," Bronson said.
"It's jagged rocks, it's sheer cliffs, it's sliding sandstone, juniper and sagebrush. That's the kind of terrain. It's not easy and not something an inexperienced person should ever consider."
LaFever stayed near the river, which gave him a chance at survival and police an opportunity to find him.
"Considering the lack of foresight that went into his trip, he did some remarkable things to keep himself alive," Utah Highway Patrol helicopter pilot Shane Oldfield told Reuters.
"He was emaciated and he couldn't walk and he couldn't crawl. He said he's been in that spot three or four days."
Police believe LaFever got a ride to a spot where the Escalante River crosses a state highway, a few miles south of Boulder.
He then followed the river into the wilderness, apparently with the goal of reaching Lake Powell and trying to get a boat ride to Page.
The sheriff's department said Ray Gardner, a Garfield County deputy, proposed a flyover of the river on a hunch. He had recently completed a search-and-rescue training class and remembered learning that people with autism are often drawn to water.
Scott Monroe, a spokesman for Garfield Memorial Hospital, said LaFever was taken there for treatment on Thursday but had since been transferred to another center.