Even when the bare mountain peaks here are snow-covered, the climate on the Copper Canyon floor is semitropical – a fact that the indigenous Rarámuri (also known, incorrectly, as the Tarahumara), depend on, migrating in winter to the warmth of the deep canyons. The Rarámuri, who were driven here after the Spanish Conquest and whose population now totals some sixty thousand, live in isolated communities along the rail line and in the surrounding Sierra Tarahumara, eking out an existence from the sparse patches of cultivatable land. Although their isolation is increasingly encroached upon by commercial forestry interests, ranchers and growing numbers of travellers, they remain an independent people, close to their traditions. Despite centuries of missionary work, their religious life embraces only token aspects of Catholicism and otherwise remains true to its animist roots, their chief deities being the gods of the sun, moon and rain. Above all, the tribe is renowned for running: a common feature of local festivals are the foot races between villages that last at least one day and sometimes several on end, with the runners kicking a wooden ball ahead of them as they go.