Mont Blanc Marathon: Chamonix's Trail Festival
The Mont Blanc Marathon is a major trail-running festival in Chamonix, offering distances from a 10K and Vertical Kilometre up to a 90 km ultra, all on the trails beneath Mont Blanc. It is a fixture of the European summer trail calendar.
The 90K (~6,500 m of ascent) is the headline ultra; the 42K and 23K are the most popular distances, and the 10K and Cross make the event accessible to newer trail runners.
Date verification: Dates for the next edition have not yet been officially announced. The Mont Blanc Marathon is traditionally held in late June — check the official website for confirmed dates.
Distance categories: 90 km · 42 km · 23 km · 10 km · Vertical Kilometre · Cross (short)
Elevation gain: 90K: ~6,500 m
Entry: Entry via the official website. Distances sell out at different rates — register early for the 90K and 42K. See the official website for current rules.
The Races
All races start and finish in Chamonix, climbing into the Aiguilles Rouges and surrounding trails. The 90K is a serious mountain ultra; the 42K is a classic alpine marathon with significant climb; the 23K, 10K and Vertical Kilometre suit a range of abilities.
The festival atmosphere, the alpine setting and the range of distances make it one of the most popular trail events in Europe.
Frequently asked questions
- How far is the Mont Blanc Marathon 90K? The headline 90K is approximately 90 km with about 6,500 m of ascent. The event also offers 42K, 23K, 10K and Vertical Kilometre distances.
- When is the Mont Blanc Marathon? Traditionally held in late June. Dates for the next edition have not yet been officially announced — check the official website.
- How do I enter the Mont Blanc Marathon? Entry via the official website. The 90K and 42K sell out fastest — register early.
Atlas Mountains Hiking — Alpine-style mountain trails in a drier, quieter range.