Camp Hale and the Altitude Problem Nobody Had Solved

When the Army built Camp Hale in nineteen forty-two, at nine thousand two hundred feet in a valley near Leadville, they understood that altitude would be a problem. They did not understand how large a problem. The men who arrived for training in the Tenth Mountain Division came from sea-level states, from cities and towns where the air was thick and the lungs did not have to work. At nine thousand two hundred feet, the air contains roughly thirty percent less oxygen than at sea level. The body knows immediately, even when the mind does not.

The Army's medical records from Camp Hale document altitude sickness cases that exceeded any other American training facility. Headaches severe enough to prevent sleep. Nausea. Impaired judgment, which in soldiers learning to fire weapons and navigate steep terrain in winter was not a theoretical problem. The incubation period before adaptation began was measured in weeks, and adaptation was partial, not complete. There was no pharmacological fix. The solution was time and exposure, which meant training suffered while the soldiers adjusted, and some soldiers never adjusted fully enough to serve at altitude.

The paradox the records document is this: the same physiological punishment that made training at Camp Hale so costly made the soldiers who survived it extraordinarily effective at lower elevations. The Italian Apennines, where the Tenth Mountain fought in nineteen forty-four and forty-five, topped out at roughly four thousand feet, well below the altitude where the men had trained. Their legs were stronger than the terrain required. Their lungs were ahead of the oxygen supply. The mountain had made them.

The camp closed after the war. The valley returned to ranch land and then to federal monument status. The altitude is the same. The air is the same. The mountains around the valley still look like what they were: the hardest training ground the United States Army operated in the twentieth century.