Limay River
Among the depressions by which the plateau is intersected transversely, the principal ones are the Gualichu, south of the Río Negro, the Maquinchao and Valcheta (through which previously flowed the waters of Nahuel Huapi Lake, which now feed the Limay River), the Senguerr (spelled Senguer on most Argentine maps and within the corresponding region), and the Deseado River. Besides these transverse depressions (some of them marking lines of ancient interoceanic communication), others were occupied by either more or less extensive lakes, such as the Yagagtoo, Musters, and Colhue Huapi, and others situated to the south of Puerto Deseado in the center of the country.