"It is still a search-and-rescue effort," Yavapai County Sheriff's Office spokesman Dwight D'Evelyn told AOL News. "[There have been] cases where there is survivability up to 96 hours, and we're right in that territory. There is no plan to terminate the search."
Sylar had been on a camping trip with Christina Priem and members of her family at the Beaver Creek Campgrounds, about 50 miles south of Flagstaff. He was discovered missing from their tent about 1:45 a.m. Sunday.
Yavapai County Sheriff's Office
Sylar Newton, 2, was last seen at a campground in Arizona on Sunday.
Temperatures in the area since Syler went missing have averaged in the upper 70s. The summer heat, combined with high humidity, has made the search difficult. And the clock is ticking.
"A lot depends on [a child's] physical health, the terrain, predators [mountain lions, bears and coyotes] and the weather," says Gary Peterson, former deputy director of Texas EquuSearch, a missing-person search-and-recovery group. "Young children like that can be pretty resilient."
According to Peterson, small children are typically found within a mile of where they were last seen, often in a place where they can crawl in for shelter.
Sheriff's deputies, along with search-and-rescue personnel and assisting units from the Coconino County Sheriff's Office, today expanded their search grid beyond the initial five-mile sweep around the campsite. Aerial searches are being conducted over a broad area, and dive teams are checking local waterways.
"We keep hoping to find a scent pattern or some evidence as to where he might be," D'Evelyn said. " Even if it's well outside the normal range, you would expect to find a 2-year-old who has wandered off."
As the search continues, the investigation has become more intense. In addition to conducting multiple interviews with individuals at the campground, authorities have completed a canvass of local sex offenders. None was found to have any involvement in the child's disappearance, D'Evelyn said.
Investigators are also continuing to interview Priem and other family members, whom they've described as "cooperative." Polygraph examinations for the family members involved in the case were scheduled for Monday, but results have not yet been released.
Priem told police she was in the process of legally adopting Sylar. While detectives have yet to verify that claim, Sylar's biological mother, Charity Newton, has reportedly said she wanted Priem to raise her son so he could have a better life.
Speaking with ABC15 Phoenix Wednesday, Newton said she is worried about her son's safety. "I have moments of hope and then moments of sheer terror," she said.
Sylar's biological father has also been identified, but police are still trying to locate him.
Meanwhile, detectives from the Criminal Investigations Bureau are continuing to examine property and vehicles that were recovered from the campsite. The vehicles are a Toyota Camry and a Toyota Corolla, which belong to Priem and her mother, Nancy Collins, respectively.
D'Evelyn says he expects more details about the case to be released in the coming days.
"If we had some indication he has been taken or where he is, obviously we wouldn't be out here," D'Evelyn said. "They're evaluating all this day by day, but as it stands now, the search will continue."
