From Mendoza traveling 47 km (29 miles) north on Ruta Provincial 52, passing through Canota, you arrive at Villavicencio, the source of mineral water sold throughout Argentina. The nearby Hosteria Villavicencio offers a simple lunch menu.
Farther up the road, the Camino del Año begins its ascent around 365 turns to El Balcón atop the pass at Cruz de Paramillo (3,000 meters/9,840 feet). Look for the ruins of a Jesuit mine, the Arucarias de Darwin (petrified trees found by Darwin in 1835), and the 1,000-year-old petroglyphs on Tunderqueral Hill. From the top of the pass you can see three of the highest mountains outside of Asia, all over 6,000 meters (20,000 feet): Aconcagua to the west, Tupungato to the south, and Mercedario to the north.
At Km 67, the road straightens and descends into Uspallata, where you can continue west on Ruta Nacional 7 to Chile or take the lonely road north on Ruta 39 (which turns into Ruta 412) onward to Barreal in San Juan Province, 108 km (67 miles) away. The road to Barreal crosses a high desert valley, where the only sign of life is an occasional ranch obscured by a grove of alamo trees.
At Los Tambillos, about 40 km (25 miles) north of Uspallata, the route is intersected by the Inca road that ran from Cusco, Peru, through Bolivia and into northern Argentina. The site is surrounded by a fence that protects traces of the original road and remains of an Inca tambo (resting place). A map shows the route of the Incas.
The mountains to the west get higher and more spectacular as you approach Barreal. At the San Juan Province border, the road becomes Ruta 412, and is paved the remaining 50 km (31 miles) to Barreal.