The Cuesta del Obispo is one of the great mountain roads of northwest Argentina, a winding climb from the green valleys near Salta to a high pass at about 3,350 metres, followed by a descent into the dry Calchaquí valley. The name means the Bishop's Slope, and it recalls a bishop of the colonial church. The scenery is magnificent, with steep green hillsides covered in cloud forest at the bottom, bare rock and golden grass at the top, and then the red, dry valley on the far side.
The ascent, on Ruta 33, is a long series of hairpins and bends, with views that open out at every turn. Much of the road is gravel, with sections of rough surface, loose stones and the odd rock fall, so ride with care and keep to the inside on blind bends. Fog is common on the climb, especially in the afternoon, and it can reduce visibility to a few metres. In summer, the rainy season, storms and landslides may close the road, so check conditions before you set out. The best season is April to October, when the weather is dry and clear.
At the summit, the pass is marked by a stone monument at a place known as Piedra del Molino, and the view across the valley is superb. Beyond lies the Los Cardones National Park, named after the giant cacti that stand like candelabras on the hillsides, some of them many centuries old. The long straight known as the Recta del Tin Tin, which crosses the valley floor, is one of the most photographed sections of road in Argentina. The wind here can be strong, and the sun is fierce.
Fill the tank in Salta before leaving, and carry water and warm clothes. At Cachí, a pretty village of whitewashed adobe houses and a small church, you can stop for lunch, with regional food such as empanadas salteñas and locro, a thick maize and meat stew. The riding is demanding, but the setting is among the most beautiful you will find.