The Colossus of Chijllani: Mesili on Illimani’s South Face

Above the gorge of the Rio Chijllani, on the southern flank of Nevado Illimani, rises one of the most terrifying precipices in the Americas: the 2,000-metre (6,600-foot) South Face.

While Conway’s 1898 normal route ascended the gentle western ridge from Nido de Cóndores, the South Face was an amphitheatre of sheer vertical ice, hanging glaciers, and granite headwalls that dropped straight into the abyss. Constant rockfall and massive serac avalanches swept the face, leading generations of climbers to consider it entirely suicidal.

Mesili’s Grand Vision

Fresh from his triumph on the West Face of Huayna Potosí in 1970, French-Bolivian pioneer Alain Mesili turned his eyes to Illimani’s southern wall. Mesili realized that traditional siege tactics were impossible on such a face; the only way to survive was speed—a lightweight alpine-style blitz that minimized exposure to falling ice.

In August 1972, during a spell of crystalline winter weather, Mesili assembled his elite team, supported by young Bolivian climbers including future mountaineering researcher Erick Monasterio. Carrying only single ropes, technical ice axes, pitons, and bivouac hammocks, the climbers hiked into the isolated Chijllani valley.

Night Ascent through the Bowling Alley

To survive the lower ice apron—notoriously dubbed “The Bowling Alley” due to rockfall peeling off the upper face under the afternoon sun—the climbers crossed the bergschrund at 2:00 a.m.

Moving rapidly under the light of headlamps, Mesili led the rope team up steep 60-degree firn ramps. The cold was searing, freezing their breath against their wool balaclavas, but the frost glued the loose rock to the face, giving them a safe passage through the lower couloirs.

By midday, they reached the central ice barrier at 5,600 metres: an imposing, 70-degree wall of blue glacial ice flanked by fractured granite buttresses. Here, the climbing became intensely technical. Mesili led pitch after pitch on front points, driving tubular ice pitons to protect the exposed moves.

The Hanging Bivouac at 5,800 Metres

As night fell, unable to find any flat ledge, the climbers had no choice but to hack out a tiny standing platform on a 60-degree ice shelf at 5,800 metres. Anchored to three pitons driven into the ice, they spent the night suspended over two kilometres of empty vertical void, watching the stars wheel across the Southern Cross.

At dawn on August 8, 1972, stiff with cold and exhausted from hypoxia, they tackled the final 600 metres. The route surmounted delicate ice flutings and tunneled through an overhanging snow mushroom to emerge on the corniced summit crest of Pico Sur at 6,438 metres.

Standing on the summit in brilliant sunlight, with the clouds of the Amazon basin churning below like an endless white sea, Mesili and his companions realized they had accomplished the greatest big-wall ice climb in the history of the Bolivian Andes. It stood as an immortal monument to alpine courage, visionary route-finding, and the golden age of South American exploration.