Marathon du Mont-Blanc

Marathon du Mont-Blanc: The Alpine Legend

Marathon du Mont-Blanc is not a standard trail running race. It is a competitive expedition around Western Europe’s most emblematic peak. Since 1999, thousands of runners and walkers have lapped Mont-Blanc in its various distances, experiencing the raw reality of high Alpine mountains: glaciers, passes above 4,000 meters, violent weather changes, and otherworldly landscapes.

The 2026 edition will maintain its essence: a race that transports you from Chamonix (French Alps) across the Italian border (Courmayeur) and back to France, accumulating over 5,000 meters of elevation gain on the long distance (88km). The 42km marathon is the “accessible” version with 2,730m, though it remains brutally demanding.

A 88km route around the Alpine massif

The 88km ultratrail is the star: it fully circumnavigates Mont-Blanc, passing through glacier landscapes, rocky ridges, and high altitude passes. Some sections are technical and rocky; others are fast hiking over snow or scree. The race touches Chamonix (France), Courmayeur (Italy), and several smaller Alpine villages in its nearly 90-kilometer circumnavigation.

The 42km marathon is a variant covering roughly half the classic circuit, with similar altitude and technical challenges but in a more manageable time (12-hour maximum). The 23km cross is the entry gateway: it covers the French side with moderate elevations by Alpine standards.

Aid stations strategically placed every 5–8km. Mandatory time cutoffs and withdrawal if running maximum allowed time.

The Alpine challenge in June 2026

June is the opportunity window in the high Alps: snow has retreated enough to allow passage, but temperatures at 4,000 meters are not unbearable. Still, weather is unpredictable: you could experience snow, hail, or blazing sun in the same morning.

Marathon du Mont-Blanc has an unofficial but inescapable requirement: prior experience in mountain trail running and the emotional resilience to handle ridgeline exposure. Some sections are highly technical and exposed; it is not a beginner’s obstacle course.

The entire race is supported by a local community (Chamonix) with centuries of Alpine rescue experience. Helicopter available 24/7. But the best prevention is arriving well-prepared.

Chamonix and Auvergne-Rhône-Alpes: Much more than the race

Chamonix is a world-famous mountain tourism hub, host of the 1924 Olympic Games and destination for mountaineers, skiers, and hikers from across Europe. Beyond the race, the region offers:

• Alpine museums: Chamonix Mountain Museum (climbing history), Musée de l’Aiguille (glaciers and geology).
• Aerial tramways: Aiguille du Midi and Mer de Glace: access to glaciers and Mont-Blanc views impossible from ground level.
• Hiking: hundreds of routes, from gentle walks to technical climbing.
• Gastronomy: Reblochon cheese, mountain fondue, and Savoyard wines.
• Access to Switzerland and Italy: nearby borders to explore Swiss Valais or Italian Aosta Valley.

You can reach Chamonix from our race planner or design your own route: Trail Running Planner. Also check our Alpine gear guides and similar races in other French regions.