Cauca
a river of Colombia, in South America, which, after a N. course of 600 miles, falls into the Magdalena. Its valley is one of the richest and most populous districts of the continent, and it gives name to one of the Colombian departments traversed by the Andean coast-range, and extending along the Pacific from Panama to Ecuador; area, 20,403 square miles; pop. about 215,000.
It is rich in minerals. Capital, Popayán.