One of the leaders of the National Outdoor Leadership School in Lander was killed over the weekend by a falling rock as he climbed a cliff in the Wind River Mountains.

Fremont County officials are investigating whether the stone that killed him was thrown by someone.

The Fremont County coroner's office confirmed Monday that it and the sheriff's office were investigating the mountaineering death of Peter Absolon, 47, Saturday afternoon. Absolon was killed as he and a climbing partner were developing a new route up the cliff face of Leg Lake Cirque south of Lander.

Absolon was the Rocky Mountain director for NOLS in Lander, and first worked for NOLS as an instructor beginning in 1990.

"We are deeply saddened by this tragedy," said Bruce Palmer, acting executive director for NOLS. "Pete was a good friend and a key member of the NOLS community. Our thoughts and sympathy are with his wife, Molly, and their daughter, Avery."

Absolon's friend, Phil Powers, president of the American Alpine Club, alleges that a rock was thrown or kicked off the top of the cirque which struck and killed Absolon as he and Steve Hirlihy, a fellow NOLS instructor, were resting 800 feet up the rock face.

In a posting to the climbers' forum at Supertopo.com, Powers wrote: "Pete was doing a new route near Lander in Leg Lake Cirque. He had completed a lead and was anchored about 800 feet up the wall. His partner had just arrived at the belay. The rock was thrown or pushed off by a hiker from the summit plateau 300 feet above. The thrower looked over the edge, saw it hit Pete, then dialed 911. The rock hit the back of Pete's helmet covered head. He must have died instantly."

Fremont County Coroner Ed McAuslan confirmed that Absolon had been fully equipped with all necessary climbing and safety gear, including a helmet, harness and rope. "A rock from above hit him in the head, and death was immediate," McAuslan said.

The coroner said Absolon's climbing partner tried but failed to raise the body up off of the cliff face, then hiked out to call for help. The remote site and late hour resulted in Absolon's body being left on the rock face overnight.

The Fremont County sheriff's office called in a specially trained climbing rangers team based at Jenny Lake in Grand Teton National Park, as well as an interagency helicopter. Renny Jackson led the seven-person team from Jenny Lake.

"We lowered two rangers to the body, with a litter, and raised the litter and a ranger to a ledge about 130 feet higher on the wall," Jackson said Monday. He credited precision flying by helicopter pilot Rick Howard in lifting the litter from the ledge and flying it to a ground vehicle at 5:30 p.m. Sunday. The entire operation took six hours, Jackson said.

McAuslan confirmed that both his office and the sheriff's office were investigating Absolon's death and emphasized that it was an active investigation, so there would be no further releases of information. He declined to comment on whether the rock that killed Absolon had been put into motion by a person, but did say the 911 caller who reported the accident was not the focus of the investigation.

In a mid-afternoon Monday telephone interview, McAuslan said an official autopsy would be held later that day.

Powers said that the "rock thrower" was among a small group of hikers, and that a fellow hiker could have made the 911 call. Powers said his information, gleaned from climbing friends in Lander, was that the "thrower" had been fully cooperative with authorities over the weekend.

"Falling rock is a significant objective hazard when rock climbing and one that requires vigilance and very careful management," said NOLS' Palmer. "Knocking rocks loose or throwing rocks purely for recreation is not prudent, particularly without first insuring that the landing area is clear of people or property."