The Long Valley area slide was about twice as big as rescue workers initially reported, Sevier County Sheriff Nathan Curtis told The Salt Lake Tribune on Saturday after visiting the scene.
Childs was raised in Gunnison and was visiting his parents for the weekend, Curtis said.
When the avalanche occurred about 4 p.m., Childs' father and brothers-in-law searched for him for about 30 minutes before anyone went for help.
"That's what they should do," Curtis said.
The Childs family was in a remote area of the Manti-LaSal National near Emerald Reservoir a site so remote that Childs' father had to ride some 10 miles west to Mayfield, in Sanpete County, before he could call emergency responders. By the time Sanpete County authorities were notified, it was 5:30 p.m, Curtis said.
Sanpete County Sheriff Brian Nielson asked Curtis' Sevier County Search and Rescue to help his team look for Childs. Nielson added that Childs had been buried for quite some time.
The two groups met up in Mayfield, which is about 7 miles east of Gunnison, and rode out to the scene on snowmobiles and snowcats, accompanied by a medical helicopter. Search-and-rescue teams from Emery and Piute counties joined in as well, using probes to look for Childs.
Five hours after the father's call, Childs was found buried under his snowmobile in about 3 to 5 feet of snow. A doctor among the searchers pronounced Childs dead. His body was transported by helicopter to a hospital in Gunnison.
The death is Utah's third avalanche-related death of the season.
Childs, from Draper, was an avid snowmobiler, an experienced rider and had been wearing a helmet. But he wasn't wearing an avalanche beacon, according to the report, nor was anyone in his group.
About 93 percent of avalanche victims can be found alive if they are dug out within the first 15 minutes, according to the Utah Avalanche Center. But the numbers drop "catastrophically" after 45 minutes when only 20 percent to 30 percent are still alive, and almost no one survives after two hours, the center reports.
The Utah Medical Examiner's Office will investigate the cause of death.