The story Bob linked to is not too far off from the fate of Mick Miller, who lived in my dorm in college, a guy I knew reasonably well. He and a couple of buddies went up to Mt. Lafayette in the fall of 1983. He had more energy and went on ahead of the other guys, said he'd meet them at the hut. IIRC, one of the people staffing the hut said he saw Mick waiting around looking impatient, and that was the last sighting of him. The speculation was that he thought the other guys must have gone by without his noticing, and he headed up to the summit and then got lost. There was a search starting the next day, and a bunch of us went up to help (the search people sent us out in groups to look along trails in places fairly far from the likely area, probably just to keep us out of their way). It had snowed overnight, and there was a lot of weird psychology going on (people spotting things that they imagined to be improvised shelters, consultations with a psychic who supposedly was going to tell us where he was). We certainly didn't find him, and as far as I know there was never any trace found. It appears that that is
still the case. For some odd reason I was thinking about him just yesterday -- I think I heard a song that reminded me of something that had happened that involved him. There were some people who speculated (with wishful thinking) that he had slipped away to secretly start a new life in East Berlin, which wouldn't have been entirely out of character. But it's not likely.