The range extends over an area about 230 km long and 25–40 km wide, stretching in a NNW-SSE direction parallel to the Pacific coast, its ridge is about 60 km from the coastline. It is part of the Andes mountain range which inland borders on the Costa, the narrow strip of coastal deserts along the South American coast. In the north and east the range is bordered by the Santa River which crosses the coastal ridge at 8° 45' S and runs parallel to the Cordillera Negra for almost all its length. In the south the range is bordered by the Patiwillka River at 10° 30'. In the central part of the range near Huaráz, Casma River breaks through the ridge of the range.