The eastern range is cut through by six rivers in Peru, namely, the Maranon and Huallaga, the Perene, Mantaro, Apurimac, Vilcamayu and Paucartambo, the last five being tributaries of the Ucayali.
The Andes lose their majestic height to the northward; and beyond Cerro Pasco the eastern chain sinks into a lower range between the Huallaga and Ucayali.
The other great rivers are tributaries of the Ucayali.
The Pozuzu, flowing eastward from the Knot of Cerro Pasco, joins the Pachitea, which is the most important northern affluent of the Ucayali.
The Vilcamayu rises on the Knot of Vilcanota, flows north through a lovely valley, received the Yanatilde and Paucartambo on its right hank, and, uniting with the Tambo, forms the Ucayali.