The summit of Denali (formerly known as Mount McKinley) is 20,310 feet above sea level, and Werner Berger was 200 feet from the peak. Just another 20 minutes of climbing and he would cross the tallest mountain in North America off his list. The weather, however, had turned nasty. And rather than risk getting caught in a whiteout, Berger’s group turned back.

“Everybody was so disappo...