April 1, 2012 -- Searchers have found the body of ultrarunner Micah True, who went missing last week after going on a 12-mile run in southwest New Mexico's Gila National Forest.

New Mexico State Police Lt. Robert McDonald told ABCNews.com that True's body was discovered "out in the wilderness," around three miles from where he was last seen. A group of True's friends had been searching for him Saturday and came across his body around 4:30 p.m. The group turned back to alert search parties, who got to the body around 6 p.m.

Since it quickly grew dark after True's body was discovered, ground crews and people on horseback returned today to excavate him. His body will be taken to Albuquerque for an autopsy, so it will likely be a few more days before the cause of death is known, according to McDonald.

"From what I've heard, there was no sign of any struggle," he said.

McDonald said the wilderness in this area of the Gila National Park is very overgrown, and even seasoned experts like True can run into trouble.

"At the end, it's just a recipe for disaster when you go out there by yourself," he said. "This is one of those things that, unfortunately, has been happening more and more lately."

True, 58, was a legend in the distance running community. He was the subject of Christopher McDougall's best-selling book, "Born to Run," which recounted how he took up residence in the remote Copper Canyons of Mexico among the Tarahumara, a desert-dwelling tribe of the best ultrarunners in the world.

After True disappeared March 27, search efforts were launched Wednesday and then ramped up across the region as the days went on.

True had spent the night at the Wilderness Lodge in Gila Hot Springs and went running Tuesday morning wearing shorts, a T-shirt and hat and carrying one water bottle, according to Jane Bruemmer, the lodge's co-owner.

"He goes for a run every day, so it's not unusual," she told ABCNews.com Saturday. "We just don't think he had much with him, since he was planning on coming home. We're perplexed."

Since True spent part of the year in Urique, Mexico, where he was the race director of the Copper Canyon Ultra Marathon, a 50-mile race across the desert.

Bruemmer said he often stayed at her lodge while en route to and from Mexico. He ran frequently among the cliff dwellings of the Gila National Forest.

Before True went missing, Bruemmer and her husband were heading to Silver City, N.M., a town about 40 miles away from the lodge, but True had planned to stay until Wednesday, when he was to depart for Phoenix to visit his girlfriend. So the couple bid him goodbye, leaving a friend to watch the lodge while they were away, Bruemmer said.

But the friend told the Bruemmers that True never returned from his run on Tuesday, and that "the guests were worried," she said. So she and her husband, Dean, called the state police Wednesday morning, and they launched a search in the area, where the temperature can drop below freezing at night.

True had left his dog at the lodge, since he would be running north along Highway 15, which dead-ends at the cliff dwellings, Bruemmer said.

True wasn't known to have any health problems, and Bruemmer suspects he may have become injured. But the search parties "have gone over and over these trails, and on really obscure trails that are barely there anymore," she said.

People have been known to get lost in the Gila National Forest, because it's a wilderness area, "so you can get turned around," she said. "But I wouldn't have thought it would happen to Micah."