The exhaustive 10-day-long search for an autistic teen who walked out of his Wyoming home during a cold spell, wearing pajamas and no shoes, was changed Wednesday from a rescue effort to a recovery effort.

Joseph Peterson, 16, walked out of his southeastern Natrona County home wearing a red hoodie and pajama pants between 11 a.m. and noon Nov. 10, according to the Natrona County Sheriff's Office. He wasn't wearing shoes when he ventured into rough rural terrain during frigid temperatures.

Natrona County Sheriff's Deputy Sean Ellis said the next day during a news conference that Joseph "is autistic who functions at a higher level, but is not self-sufficient and does not problem-solve at an age-appropriate level."

"Joseph has no concept of action versus consequence," Ellis said. The teen's decision to leave the house was a "misguided choice," Ellis said. Foul play was not suspected.

Joseph Peterson. Natrona County Emergency Management

"Factoring in the time frame, lack of clothing Joey was wearing, no food source and extreme weather conditions, the search for Joey at this time is consistent with a recovery," Taylor Courtney, a Natrona County Sheriff's Office spokesman, announced Wednesday.

Courtney said that the search for the teen's body was ongoing, but asked that volunteers cease their efforts to find him, as a snowstorm approached the area. "We don’t want to have another incident where we have to send search and rescue back out," he said.

Hundreds of volunteers, more than a dozen county, state and federal agencies, horses, K-9s, fixed-wing aircraft, drones and helicopters were utilized in the desperate search for the teen.

"This is about the largest-scale search that I have ever seen," Courtney said. "We have utilized every single available resource that we can."

"I think we have a lot of really exhausted people, but I don’t think they would tell you that," he added. "I think they would tell you that this is a very worthy cause, and we have a young man out there that we want to bring back to their family no matter what."

Shortly after Joseph left his home, a witness who did not know it was him at the time saw him traveling south. Three bloodhound teams verified that the teen had traveled south by discovering barefoot prints, but the search "expanded in all directions proportionately to the amount of time that had passed," Courtney said.

In all, 250 square miles were covered in the search for Joseph.

"One of our members logged 109.6 miles of hiking" in steep and rugged terrain full of downed trees and mudslides, Courtney said, where the elevation varies from 5,200 and 7,200 feet. "This search has tested our limits."

The first set of footprints found indicated Joseph was bleeding from his left foot, Courtney said.

More footprints, in snow, belonging to him were found Nov. 16, about 3 miles from his home at the base of Casper Mountain. Courtney said the days-old footprints were likely from "soon after he left the residence," and since he probably took the "path of least resistance" to the base of the mountain, the teen could have walked as many as six miles in the cold.

"How that affected him, we won’t know until we find him," Courtney said.

The recovery search will be coordinated by the Natrona County Emergency Management division, and will be smaller and more focused based on drone and other data previously gathered.

"We want Joey home," Courtney said. "All of us do."