Mont-Blanc 23K is the 23.0km trail race at Mont-Blanc Marathon 2027 (Chamonix, France). The race starts on June 26, 2027.
Hold a steady pace and save energy for every section.
The course climbs 1680m+. With 73m/km of climbing, the course is exceptionally steep, with long hiking-grade sections. By gradient, 54% of the distance is uphill, 27% downhill and 19% flat. The longest climb runs 8.7km at an average 8.9% grade (773m of vertical). The longest descent runs 1.2km at an average 21.7% grade (269m of vertical). The steepest climb averages 24.0% over 0.9km. The steepest descent drops at 25.8% over 1.0km. Surface: 88% trail and 6% road.
The course also passes close to Le Béchar (1720m).
Trekking poles are worth taking: about 4.3km of the course favours them.
Quad damage risk is low (index 10 of 100): a few descents worth noting, none of them decisive.
This page has a pacing and nutrition planner, a gradient matrix, an interactive elevation profile and historical weather for Mont-Blanc 23K.
Other distances of Mont-Blanc Marathon 2027Mont-Blanc 42K (42.0km)·Mont-Blanc 10K (10.0km)·Mont-Blanc KM Vertical (3.8km)
Other editions of Mont-Blanc 23K2026
Official websitewww.marathonmontblanc.fr/en