AVALANCHE

Alaska, Mount McKinley

On the evening of June 15, 1982, a North Cascades Alpine School (NCAS) expedition of four and the Valley Mountaineers expedition of four were camped at the 3900-meter level on the West Buttress of Mount McKinley. On the same day, a Fantasy Ridge and a Mountain Trip expedition made a carry to the same elevation and cached some of their gear, before retreating to their lower camp.

It was snowing very heavily (2½ centimeters per hour) and the wind was blowing out of the southeast at 35 knots. The storm continued throughout the night, and 18 centimeters of “fairly wet snow” had accumulated by 2000. On July 16, early in the morning, avalanches could be heard breaking away from the gullies on the West Buttress. At 0630, a large slope on the West Buttress released that buried all of the NCAS tents and totally buried the Valley Mountaineers’ camp with 60 centimeters of snow. The Valley Mountaineers were thrown out of their tents and one climber was buried for almost 20 minutes. They needed assistance from the NCAS in digging him out as they had lost their shovels in the avalanche. No one else was injured but both tents were destroyed and various gear was reported lost. The caches that had been left the day before were also buried. The Mountain Trip group was able to find its cache while the Fantasy Ridge expedition was unable to recover all its gear and retreated to base camp. (Source: Roger Robinson, Mountaineering Ranger, Denali National Park)

Analysis

The 3790-meter camp on the West Buttress is a potentially dangerous location during unstable conditions. The camp can be avoided by continuing up to 3900 meters and camping in the bergschrund, or by camping well below the potential remount slope on the Buttress. (Source: Roger Robinson, Mountaineering Ranger, Denali National Park)