Cauca, a river of South America, rising in that part of the Colombian Andes called Paramo de Guanacos, in the United States of Colombia, lat. 2° N, lon. 76° 30' W. On descending from the mountains, its course is W. until about 15 m. W. of the town of Popayan, where it bends N., and flows with the impetuosity of a mountain stream almost parallel to the Magdalena, which river it enters at the town of Nechi, lat. 9° N. The whole course of the Cauca is about 600 m.; it is navigable only for small craft, and not above Cali, which, with Toro, Buga, Antioquia, and Neehi, are the principal towns upon its banks. The valley which it waters, lying between the W. and central Cordilleras of the Andes, is one of the most fertile in the western continent.
Cauca, a state of the United States of Colombia, bounded N. by the Caribbean sea, E. by Cundinamarca, S. by Ecuador, and W. by the Pacific ocean; area, 260,000 sq. m.; pop. about 435,000. It is traversed by the river of the same name, and is one of the richest, most fertile, and most populous districts in South America. It consists of two plateaus of different elevation, and consequently of different temperature; the land is well cultivated, and produces the various cereals, coffee, sugar, tobacco, cotton, and cocoa, the last being especially abundant; and vast and rich pastures afford nourishment for innumerable herds of cattle and mules. The fields and farmhouses present the appearance of wealth and comfort. Gold has been found in the upper part of the valley. Capital, Popayan.