River, south-central Argentina.
Its major headstreams, the Grande and Barrancas rivers, flow southward from the Andes Mountains and meet to form the Colorado near the Chilean border. It flows southeastward across northern Patagonia and the southern Pampas . Its lower course splits into two arms that flow into the Atlantic Ocean south of Bahía Blanca. Its total length is about 530 mi (850 km).