John Mallon Waterman, 28, vanished during a solo climb of Mount McKinley (Denali) after leaving the Sheldon Amphitheater’s Mountain House on April 1, 1981. He was last seen heading up the northwest fork of the Ruth Glacier toward the East Buttress, pulling a red plastic sled and travelling without ropes through heavily crevassed terrain.

Waterman traveled with minimalist supplies: 14 days of food (powdered milk, honey, sugar, flour), no tent or sleeping bag, a bivi sack, a snowmobile suit, VB boots, snowshoes and about 20 wands to mark his route. He returned a borrowed CB radio before the climb, saying he didn’t think he would need it. Friends noted he seemed less cautious and more run down than usual.

Searches were launched when he became five days overdue. Air and ground crews combed the Ruth Glacier and East Buttress despite high winds and snowfall that obscured tracks; an old campsite was found but no sign of Waterman. He was never located, and investigators considered crevasse fall, avalanche, or exposure possible explanations.