The first ascent of the South Face of Aconcagua

A day’s drive up the Trans-Andean Highway from Mendoza, in one of Argentina’s prime wine-growing regions, is the ranger station at the entrance to Aconcagua Provincial Park. Here climbers on Aconcagua’s Normal Route will stare up the Horcones Valley and get their first good sight of the mountain they have come to climb.

At 6,959m, Aconcagua is one of the Seven Summits. It is the highest mountain in South America, the Southern Hemisphere, and the Western Hemisphere (whatever the *$! that means...