Marathon du Mont-Blanc

The Marathon du Mont-Blanc is a cornerstone of alpine trail running. Created in 1979 by Georges Costaz as the Cross du Mont-Blanc under the banner of the Club Alpin Français, it grew into a full trail festival when the marathon distance was added in 2003. Today, over 10,000 runners gather in Chamonix every June for three days of racing that celebrate mountain running at its finest, with eight events ranging from short family courses to the demanding 90 km ultra.

The flagship 42 km marathon is a spectacular loop through the heart of the Mont-Blanc valley. Starting from the Place de l'Église in Chamonix, runners climb to the Brévent at 2,525 m before descending through the Aiguilles Rouges nature reserve, passing La Flégère and crossing the Col des Montets with sweeping views of the glacier d'Argentière. The course packs 2,540 m of elevation gain into technical trails that alternate between steep ascents, exposed ridgelines and fast descents through alpine forests. For ultra runners, the 90 km pushes further with 6,330 m of climbing across high passes and remote valleys.

What sets this event apart is the sheer grandeur of its setting. Every step unfolds against a panorama of glaciers, granite spires and eternal snow. The atmosphere in Chamonix during the festival is electric, with the town's mountaineering heritage blending seamlessly with the energy of the global trail running community. From the Vertical Kilomètre to the Duo Étoilé night run under the stars, every format finds its audience in this legendary mountain playground.