Mount Aconcagua, the highest mountain peak in the Americas (Western Hemisphere) at 22 830 feet (6958 meters) above sea level, is visible near the center of this low-oblique, northeast-looking photograph. Five major snow-covered peaks with summits exceeding 20 000 feet (6100 meters) rise along the north-south axis of the cohesive and massive structure of the Andes Mountains through this area of Argentina and Chile. Mount Aconcagua is the second snow-covered peak from the north. The narrow east-west valley immediately south of Mount Aconcagua contains a section of the Pan American Highway that connects Mendoza, Argentina, with Santiago, Chile. Mount Aconcagua and the snowcapped volcanic peak north of Mount Aconcagua lie within Argentina; the three snowcapped volcanic peaks south of Mount Aconcagua lie directly on the Chile-Argentina border. Several river basins are discernible on the eastern side of the Andes Mountains in west-central Argentina. Where sufficient water exists, mainly from snowmelt from the Andes Mountains, irrigated agriculture occurs in the otherwise dry valleys and basins east of the high Andes Mountains.