Copper Canyon is not one canyon but six, a sprawling network of gorges that six rivers have cut through the Sierra Madre of northern Mexico. Taken together they cover far more ground than the Grand Canyon, and the deepest of them, the Barranca de Urique, drops 1,879 metres from rim to river — the deepest gorge in North America. The name misleads, because there is little copper here. The walls take on a green-copper tint from the lichen clinging to the rock, and early Spanish travellers read it as metal. What makes the place feel like several countries stacked together is sheer elevation. The pine and oak forests of the rim hold snow in winter, while the canyon floors more than a kilometre below stay warm and semi-tropical the year round. Threaded through this vertical world are the Rarámuri, or Tarahumara, perhaps 50,000 to 70,000 people who are famous far beyond Mexico for how far they can run.
The classic way in is the Chihuahua–Pacific railway, El Chepe, which climbs from Los Mochis on the coast to the city of Chihuahua across 673 kilometres, 37 bridges and 86 tunnels. At Divisadero the train halts for about fifteen minutes on a lip of rock where three canyons open at once, and the ground simply falls away beneath the platform. From there a cable car glides out over the gorge and one of the world's longest ziplines drops toward the depths. You can still ride all of it today. The corridor from Creel to Urique is a working tourist route rather than a protected wilderness. This is a Chihuahua state park, not a UNESCO site, and most visitors keep to the train and the rim-side towns.