With World War II looming in Europe, the U.S. Army had no troops trained for mountain operations and none of the specialized equipment that the European armies had developed.

The day after Christmas 1969, five robust young men set out to climb the imposing north face of Mount Cleveland in Glacier National Park. One of the highest vertical walls in the United States, the face had never before been scaled--and certainly not in winter, when it was bound with ice. But the mountain was to become a memorial for the boys. After they failed to return to their families, an aerial search found the boys' tracks dead-ending at the...