Denali National Park and Preserve Mountaineering Summary, 1987. For the second year in a row, a new record was set for the number of mountaineers attempting to climb Mount McKinley. Despite the increase in attempts, extended periods of poor weather throughout the Alaska Range resulted in the lowest success rate since 1971. The previous winter’s snowfall was about average. However, extended periods of clear weather during the late winter and early spring created extensive avalanche conditions. At least five and possibly six persons died in avalanche-related accidents within the boundaries of Denali National Park and Preserve. An Alaskan team, Art Mannix and Chris Leibundgut, attempted a winter ascent of the South Buttress of McKinley from the west fork of the Ruth Glacier. They reached 15,000 feet before frostbite caused their retreat. The only other winter mountaineering in the park was a first winter ascent of Mount Silverthrone by Alaskans Brian and Diane Okonek and Rick Ernst. The High Latitude Research Project was not funded this season, but a short research was conducted by medical personnel. Dr. Peter Hackett coordinated the project in which they investigated a possible link between retinal hemorrhaging and cerebral edema of climbers at altitude. Following the completion of the project, the Mountaineering Rangers staffed the camp for the remainder of the season. Once again, the transportation of the camp to and from the mountain was provided by the U.S. Army, 242nd Aviation Company, Fort Wainwright, Alaska. The National Park Service conducted two 3-week expeditions on Mount McKinley, all on the West Buttress. We continue to emphasize environmentally sound expeditionary climbing and sanitation practices. In addition, mountaineers are encouraged to conduct their own evacuations whenever possible. During emergencies, the 14,200-foot medical-and-rescue camp serves as a base from which most Mount McKinley rescue operations are coordinated.