88
km
6,200
D+
2,500
max alt.
FORMATS
Course
The 90km du Mont-Blanc is the marquee race of Chamonix's marathon week: 88 kilometers and 6,200 meters of elevation gain, with an average altitude consistently above 2,000 meters. The loop course from Chamonix crosses snowfields, exposed slabs, and technical passages that make it impassable without solid high-mountain preparation. The organizers recommend a minimum UTMB index of 450 points — a serious warning for a race with a light entry filter.
Weather windows are tight in late June: late snow possible, frequent afternoon storms. Eight aid stations do not cover the nutritional gaps of a 14-plus-hour effort at altitude. Average gradient far exceeds most alpine ultras. Listed on the UTMB Index calendar, the 90km sets the benchmark in the high-technical, extreme-elevation category. 2026 edition: Friday June 26, 4:45 AM start from Chamonix.
Race profile
90km du Mont-Blanc is a 88 km trail race with 6,200 m of elevation gain, located in Chamonix, Haute-Savoie. The next edition is scheduled for 26 June 2026.
The course reaches a maximum altitude of 2,500 m. The race is rated — ITRA points and features terrain. 1 distances are available for runners.
Find all official information on the race website.
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Practical info
OFFICIAL LINKS
60 seconds. Built on the ITRA / UTMB / B-Trail databases.
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