Saint-Michel-les-Portes to Gresse-en-Vercors Mountain Pass Route

The road section discussed here is located in the Auvergne-Rhône-Alpes region of France, connecting the small villages of Saint-Michel-les-Portes and Gresse-en-Vercors. This route lies within the Massif du Vercors, a subrange of the French Prealps, which itself is part of the larger Alps mountain system. The road ascends to the Col de l'Allimas mountain pass at an elevation of 1,352 m (4,436 ft). The surrounding terrain is mountainous and forested, typical of the Vercors massif. An interactive map showing the road can be found at the end of this article.

The road is approximately 12.2 kilometers (7.6 miles) long and is surfaced with asphalt of generally good quality, rated at 4.3 out of 5. The route is moderately twisty, with a curviness rating close to 2 on a scale where 3 is extremely curvy. Most of the road (about 71%) consists of two lanes, while a smaller portion (16%) is single-lane. The width varies, with about half the road being of medium width, one-third wide, and the remainder narrow. Approximately one-quarter of the route passes through inhabited areas, primarily near the start and end villages.

Elevation ranges from 810 m (2,657 ft) at the lowest point to 1,360 m (4,462 ft) at the highest, near the Col de l'Allimas. The road includes several named segments such as Route de Saint-Michel, Route du Mont Aiguille, Route du Col d'Allimas, and Route du Prayon, reflecting the local geography and landmarks.

The key feature of this route is the Col de l'Allimas, a mountain pass at 1,352 m (4,436 ft) elevation. This pass provides a critical crossing point within the Massif du Vercors, a notable mountain range known for its limestone cliffs and plateaus. The Massif du Vercors is part of the broader Alps mountain system, which extends across several European countries. The road offers access to natural landscapes characteristic of this region, including forested slopes and alpine meadows.

For more information on the mountain ranges, see Massif du Vercors and Alps.

The road is suitable for motorcycling with its mostly well-maintained asphalt surface and moderate curviness. Riders should be prepared for variable road widths and occasional single-lane sections. The elevation gain to the Col de l'Allimas means weather conditions can change rapidly, especially outside of summer months. The route is open year-round, but winter conditions may affect accessibility due to snow or ice. There are no known tolls or entrance fees on this road, but riders should verify current conditions before travel.

This article focuses on the road section visible on the map below, which highlights the route from Saint-Michel-les-Portes to Gresse-en-Vercors via the Col de l'Allimas. The map provides a visual reference for the road's course through the Massif du Vercors and its elevation profile.