Ruta Nacional 40 Paso de Agua Negra to Rodeo

The approach to Paso de Agua Negra climbs through some of Argentina’s most brutal high-altitude desert, where abandoned copper mines dot the landscape like tombstones. Starting from Rodeo, the route follows RN40 through the Iglesia Valley before branching onto secondary tracks that wind past the ruins of Mina La Mejicana, where nineteenth-century miners extracted silver until the altitude and isolation broke them. At 4,770 meters, this is one of Argentina’s highest vehicle-accessible passes, where engine performance drops to half and every breath feels stolen.

This is expert-level territory demanding high-clearance 4WD, emergency oxygen, and cold-weather gear even in summer. The route requires two full days with overnight camping at intermediate elevations to acclimatize properly. Best attempted April through November when snow doesn’t block the final approach. Carry extra fuel, water, and spare parts—the nearest mechanic is three hours away in Rodeo. What you get is raw Andean wilderness where condors ride thermals above 5,000-meter peaks and the silence is absolute.