The region south of the Colorado River in Argentina is Patagonia, which is bordered by the Andes Mountains to the west, the Atlantic Ocean to the east, the Strait of Magellan to the south and the Colorado River to the north. Patagonia also covers a portion of Chile.
Patagonia encompasses the southern part of Argentina and measures 260,000 square miles. As a semiarid scrub plateau, the area consists of nearly treeless steppes or plains. The region includes the Argentine provinces of Neuquén, Río Negro, Chubut and Santa Cruz, a portion of Tierra del Fuego and the southern part of the province of Buenos Aires.