Cañón del Pato (Spanish: Duck Canyon) is on the Rio Santa (Santa River) at the north end of the Callejón de Huaylas (Corridor of Huaylas) in north-central Peru. The mostly rocky canyon walls are too steep and arid for cultivation, and in only a few places are the slopes of the imposingly rugged canyon suitable even for grazing domestic animals. The canyon was formed by the river where the north end of the Cordillera Negra range (to the west) converges with the Cordillera Blanca mountain range (to the east). These two Andean ridges run generally parallel for nearly 140 km from south of the city of Huaraz northward to the Cañón; the Cordillera Blanca continues northward for another hundred kilometers or more.