Alaska, Mount McKinley
On May 9, 1989, Elfi Hallinger (42) a member of a German ski traverse expedition, developed high altitude pulmonary edema (HAPE) at 4300 meters on the West Buttress route of Mount McKinley. After treatment at the Denali Medical Camp, Hallinger descended to the Southeast Fork of the Kahiltna Galcier arriving May 11, after a fixed-wing evacuation from 3000 meters was unsuccessful due to poor visibility. The party descended further to Kahiltna airstrip where a flight out occurred at 1930. (Source: James Litch, Mountaineering Ranger, Denali National Park)
The party had taken six days to reach the 4300 meter camp (most parties take from five to seven). Although this is considered a normal ascent rate for this route, a small percentage of climbers may still develop serious altitude illness. In this case, HAPE developed without any early warning signs.
During the evacuation effort, the party continued the descent rather than wait for the weather to improve for the fixed-wing pick-up. The decision to continue the descent reflected party self-sufficiency and an understanding of the importance of not delaying descent with serious altitude illness. This decision may have avoided medical complications, spent time, and expense. (Source: James Litch, Mountaineering Ranger, Denali National Park)