42km du Mont-Blanc
42km du Mont-Blanc is Chamonix's marquee mountain marathon, pairing a 42 km trail route with 2,540 meters of climbing and strict cutoff pressure.
Every link above goes to the race, its timing provider, or an official registration partner. Last checked August 4, 2026.
Quick facts
- Marathon-distance trail race in the Marathon du Mont-Blanc weekend.
- 42 km route with about 2,540 meters of elevation gain and loss.
- Limited to 2,300 runners with six start waves.
- Semi-autonomous race format with listed cutoff points.
- Livetrail live tracking and a 42 km results hub are available.
About the 42km du Mont-Blanc
42km du Mont-Blanc is the headline marathon-distance race of the Marathon du Mont-Blanc weekend. It is built for trail runners who want Chamonix terrain, big climbing, and a competitive mountain-running field rather than a road marathon.
Course
The race covers 42 km with about 2,540 meters of elevation gain and loss. It is a semi-autonomous trail race with multiple feed stations, six start waves, and cutoff pressure across the route back to Chamonix.
Race-day weather
Late June in Chamonix can move from cool valley conditions to exposed mountain sun, wind, or storms. Runners should plan for changing alpine weather and slower effort on climbs and descents.
Past 42km du Mont-Blanc dates and results
| Year | Date | Status | Results |
|---|---|---|---|
| 2026 | Sunday, June 28, 2026 | Completed | Open results |
| 2025 | Sunday, June 29, 2025 | Completed | Open results |
| 2024 | Sunday, June 30, 2024 | Completed | Open results |
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Ran the 2026 42km du Mont-Blanc?
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42km du Mont-Blanc FAQ
When is the 42km du Mont-Blanc?
We're waiting for the finalized date for the 2027 42km du Mont-Blanc. The most recent running was on Sunday, June 28, 2026.
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