PHOENIX -- A 22-year-old man missing for more than a week in the mountains of northern Arizona went into the woods for a planned five-day hike without a cellphone or any food because he was fasting, authorities said Thursday.
Thomas Lang was last seen Dec. 18 at the Manzanita Campground in Oak Creek Canyon north of Sedona.
He was dropped off by his father, who expected to pick his son up on Dec. 22. When Lang failed to show up, his family called authorities.
A fifth day of searching roughly 30 square miles of thick scrub, deep canyons and caves ended Thursday with no clues. Future efforts will be assessed overnight.
While Lang carried water and a sleeping bag, he set out on the trip without food because he was fasting, said Dwight D'Evelyn, a spokesman for the Yavapai County Sheriff's Office.
"To what extent and why, we don't know," D'Evelyn said. "But he did not take food with him. That's been made very clear."
About 60 searchers scoured the area Thursday along with a dog team and a helicopter. Experts trained to navigate the deep canyons also were brought in from the Maricopa County Sheriff's Office.
It wasn't immediately clear how far Lang planned to hike over the five days. His family hasn't returned telephone calls from The Associated Press.
They told authorities he is an experienced outdoorsman with extensive wilderness skills, but searchers have yet to turn up a clue.
"He knows about the earth and the variations of the weather, but we're not sure he was adequately prepared for how cold it has gotten at night up here," Lang's mother, Laurie Breihan, told KPNX-TV.
Temperatures in the area have been dropping into the 30s at night.
D'Evelyn said that given Lang's outdoor experience, searchers had hoped he might light a fire to signal his location.
"That's not been the case. We have not seen any fires," D'Evelyn said. "And he's got a four or five day head start on us, so it's very frustrating, but we're still holding out hope.
"The only other possibility is that if he somehow left, either hitchhiked or walked out, then he could be safe and sound somewhere," he added.
Authorities have received reports from people who claim to have seen Lang in convenience stores in the area and are checking surveillance footage, but they have yet to come up with any leads.
Lang is described as a 6-foot-1 male, weighing about 140 pounds with long blond hair and dreadlocks.
He was last seen in the campground carrying his sleeping bag, a guitar and backpack.