The Monte Desert is a South American desert, lying entirely within Argentina and covering approximately the submontane areas of Catamarca, La Rioja, San Juan, San Luis and Mendoza Provinces, plus the western half of La Pampa Province and the extreme north of Río Negro Province and Chubut Province. The desert lies southeast of the Atacama Desert in Chile and Peru, north of the larger Patagonian Desert, east of the Andes and west of the Sierra de Córdoba.