Copper Canyon is a group of canyons consisting of six distinct canyons in the Sierra Madre in the southwestern part of the state of Chihuahua in Mexico. The overall canyon system is larger and portions are deeper than the Grand Canyon in neighboring Arizona. The canyons were formed by six rivers which drain the western side of the Sierra Tarahumara (a part of the Sierra Madre Occidental). All six rivers merge into the Rio Fuerte and empty into the Sea of Cortez.