Col de Sarenne, Mountain pass in Clavans-en-Haut-Oisans, France

The col de Sarenne is a mountain pass in the Grandes Rousses massif in the Isère department of France, sitting just below 6,560 feet (2,000 m). It links the valley of Alpe d'Huez with the Ferrand valley, and the road crossing it is narrow and winding, with no guardrails on certain sections.

The pass was first used by the Tour de France in 2013, on stage 18, after an initial climb of Alpe d'Huez; Tejay van Garderen crossed the summit first, and Christophe Riblon won the stage after the descent. In 2026 it appeared on stage 20 as a Hors catégorie climb, the first time the full ascent from the east was raced, with Sepp Kuss leading over the summit. The 2013 use drew criticism from Tony Martin over the narrow road and its unguarded descent.

The pass is crossed by the long-distance hiking trail GR 54. In cycling, it entered the Tour de France in 2013 on stage 18, climbed after a first ascent of Alpe d'Huez; the descent drew criticism from Tony Martin for its narrow surface and missing guardrails. In 2026 it was climbed for the first time by its eastern side, on stage 20, rated Hors catégorie, with spectators banned for several kilometres and no publicity caravan.

The road over the pass is only open in summer, as snow closes it in winter. Driving or cycling along this narrow route calls for care, since some sections are steep and lack safety barriers.

Near the pass, dark seams of coal are still visible in the rockface, left over from old mines that once supplied the local area. Close by stands the Cassini Cross, marking the exact spot chosen by the surveyor Cassini in 1739 to map the surrounding land.