A climber trying to stop a sliding backpack fell more than 1,000 feet to his death on Mount McKinley in Denali National Park, becoming the first fatality of the mountain's climbing season, according to park officials.

The unidentified climber was with two others. They were climbing, unroped, Friday afternoon along the West Buttress route to the summit and had gotten to 16,200 feet at the top of the "headwall," or "fixed lines" section, when the fall occurred, a park release said.

The climber's body came to rest roughly 1,100 feet down the north face, on the Peters Glacier at an elevation of 15,100 feet, the release said.

At the time of the fall, a Park Service mountaineering patrol was ascending the fixed lines shortly behind the 3-member team. The patrol quickly arrived at the fall site and immediately contacted fellow rangers via radio to initiate a helicopter response. At 5:15 p.m., Denali National Park’s A-Star B3 helicopter launched from Talkeetna in clear, calm weather conditions.

With two ranger-paramedics on board, the helicopter flew to the location of the victim. NPS rangers confirmed that the climber had died of injuries sustained in the fall. The body was recovered and flown back to Talkeetna.

The identity of the victim is being withheld pending notification of family members overseas.

There are currently 336 mountaineers attempting routes on Mt. McKinley. Four climbers have reached the summit this season. This fatal fall is the first serious incident on Mt. McKinley of the 2012 mountaineering season.