Col d’Ornon (South side)

Col d’Ornon (South side)

The Col d’Ornon is a mountain pass in the Isère department, serving as the primary geographical link between the Romanche valley to the north and the Beaumont region in the Drac valley to the south. It separates the Grand Rousses and Écrins massifs to the east from the Taillefer massif to the west. Geologically, the pass sits on a foundation of sedimentary rock and crystalline basement typical of the Dauphiné Alps, creating a relatively low-altitude breach compared to the surrounding 3,000-meter peaks. The topography is defined by the Petit Taillefer to the west and the Tête des Filons to the east, forming a corridor through which the Lignarre river flows.

The road connects Le Bourg-d’Oisans to La Mure, passing through the village of Ornon. The northern approach is characterized by a steady climb through narrow, wooded gorges, while the southern side opens into wider alpine pastures near Entraigues. The Tour de France first utilized this route in 1954, with Jean Dotto crossing the summit first. Since then, it has appeared in over 35 editions, often serving as a strategic opening or transitional climb between the Oisans valley and the higher peaks of the southern Alps. Notable riders who have led over the summit include Federico Bahamontes in 1964 and Bernard Hinault in 1979. Because the pass is lower in elevation than neighboring giants, it is frequently used by the peloton to establish early breakaway groups before the final ascents of the day.