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.

Next raceSunday, June 28, 2026
LocationChamonix-Mont-Blanc, France
Boston qualifierNo

42km du Mont-Blanc 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.
  • No dedicated current-year results or live tracking URL was validated.

What is 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.

42km du Mont-Blanc course route

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.

Weather for the 42km du Mont-Blanc

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

YearDateStatusResults
2026Sunday, June 28, 2026

42km du Mont-Blanc FAQ

When is the 42km du Mont-Blanc?

The 2026 42km du Mont-Blanc is on Sunday, June 28, 2026.

How do I register for the 42km du Mont-Blanc?

You can register for the 42km du Mont-Blanc at marathonmontblanc.fr.