Acay Mountains

The Acay Mountains rise around Nevado de Acay in the La Poma Department of Salta, above the Calchaquí valley. The highest summit reaches about 5,950 metres and forms the crown of the Cuesta del Acay range. Its exposed monzonite mass belongs to a broad fault system linking nearby volcanic centres, while much older Precambrian and Cambrian rocks crop out below the younger intrusion.

Snow lies on the summit during winter, and summer storms can add more. Meltwater drains into streams feeding the Salado, Juramento and Los Patos systems, though some water ends in enclosed basins and evaporates. In this arid highland, the mountain is therefore both a conspicuous landmark and a vital divider between drainage routes.

People entered the high country long before the Spanish conquest. Inka worshippers built a sanctuary near the summit and subsidiary shrines on Blanca and Navaja; more than fifty structures occupy lower slopes between roughly 4,500 and 5,000 metres. Herders and miners used the surrounding valleys, and Spanish authorities worked gold and silver there. The Acay range thus joined routes, pasture, sacred places and mineral wealth in one highland system. Seasonal trails linked the shrine, pastures and mining valleys, making the range a corridor as well as a barrier.