Cody Moore, a member of a junior ROTC unit, seemed alert while sitting on a stretcher inside an ambulance. A woman who appeared to be a relative said he was fine and eating a doughnut.
Helicopters, horses and dogs had been searching for Cody since he was reported missing about 5 p.m. Sunday. He was wearing only a long sleeve T-shirt and sweatpants. Temperatures early Monday dipped into the 20s in that area, CBS News affiliate KHOU-TV in Houston.
A hovering search helicopter apparently alerted the boy Monday, said Duane Adams, director of the weekend exercise in using maps and compasses to navigate.
"He came out waving his hands and walking on his own," Adams said. "The helicopter hovered over him and the ground crew went in to get him."
The student from Crosby Junior High School in suburban Houston had a map and a compass when he went into the woods shortly before 11 a.m. Sunday as part of a navigation exercise. The eighth-grader was one of 300 to 400 other children participating in the exercise, reports KHOU.
"Apparently what he did was what we call a 180-degree error," Adams said. "He went north instead of south."
He said tracking dogs followed Moore's scent to a road that was intended as a boundary. But the disoriented 13-year-old crossed it and headed north in the woods marked by towering pine trees, choking brush and occasional streams, he said.
"We're elated that they found him and that he's OK," Adams said. "We're obviously always worried about this."
The event sponsored by the Houston Orienteering Club attracted some 350 people to the huge Sam Houston National Forest north of Houston.