The original 174 km loop around Mont-Blanc through France, Italy and Switzerland
Other trail races within 51 miles
The race that started it all in 2003 and gave its name to the UTMB World Series. The course is a single loop of the Mont-Blanc massif, starting and finishing in Chamonix and following the Tour du Mont-Blanc through three countries: over the Col du Bonhomme and Col de la Seigne into Italy, down to Courmayeur, along the balconies of the Italian Val Ferret, over the Grand Col Ferret into Switzerland, then back through Champex-Lac, Trient and Vallorcine to the finish in the centre of Chamonix. The Friday-evening start means every runner faces at least one night in the mountains, and most face two. As the 100M final of the UTMB World Series it draws the deepest elite field in the sport, while thousands of amateurs share the same course and a time limit of about 46 hours.
Recommended for seasoned ultrarunners
Chamonix, Haute-Savoie, FranceAugust 28, 2026
UTMB – Ultra-Trail du Mont-Blanc is a loop trail race in Chamonix, Haute-Savoie, France, held on August 28, 2026. The course covers 174 km, climbs 9,700 m, and has a 45h30m cutoff.
Entry via the UTMB World Series lottery: pre-register in January with at least one Running Stone and a valid 100K/100M UTMB Index; each Running Stone adds to your odds. Group entry is possible (the group draws with its lowest Running Stone count). Applicant and place totals are not published.
Must complete a 100K race or longer within the qualification window
A valid UTMB Index in the 100K or 100M category is required, plus at least one Running Stone earned in the previous 24 months to enter the lottery. More Running Stones improve the odds. Elites enter directly by qualifying through UTMB World Series events and Majors.
| Location | km | Elevation | Cutoff | Crew | Drop bags |
|---|---|---|---|---|---|
Chamonix Start | 0.0 | 1,035 m | — | ||
Col de Voza Checkpoint | 14.4 | 1,663 m | — | ||
Saint-Gervais Aid Station | 22.9 | 809 m | 4h15m12:00 AM +1 | ||
Les Contamines Montjoie Aid Station | 32.4 | 1,147 m | 6h15m2:00 AM +1 | ||
La Balme Checkpoint | 41.1 | 1,706 m | 8h15m4:00 AM +1 | ||
Refuge de la Croix du Bonhomme Checkpoint | 46.9 | 2,448 m | — | ||
Les Chapieux Aid Station | 52.2 | 1,546 m | 11h30m7:15 AM +1 | ||
Col de la Seigne Checkpoint | 62.9 | 2,511 m | — | ||
Lac Combal Aid Station | 67.8 | 1,965 m | 15h15m11:00 AM +1 | ||
Arête du Mont-Favre Checkpoint | 71.8 | 2,410 m | — | ||
Checrouit - Maison Vieille Aid Station | 76.4 | 1,961 m | — | ||
Courmayeur Aid Station | 81.3 | 1,194 m | 18h30m2:15 PM +1 | Drop Bags | |
Refuge Bertone Aid Station | 86.6 | 1,979 m | — | ||
Refuge Bonatti Checkpoint | 94.2 | 2,025 m | — | ||
Arnouvaz Aid Station | 99.4 | 1,779 m | 23h30m7:15 PM +1 | ||
Grand Col Ferret Checkpoint | 104.0 | 2,527 m | — | ||
La Fouly Aid Station | 114.0 | 1,604 m | 28h11:45 PM +1 | ||
Champex-Lac Aid Station | 127.5 | 1,472 m | 31h45m3:30 AM +2 | Drop Bags | |
Plan de l'Au Checkpoint | 132.4 | 1,340 m | 33h4:45 AM +2 | ||
La Giète Checkpoint | 138.9 | 1,885 m | — | ||
Trient Aid Station | 144.0 | 1,303 m | 37h15m9:00 AM +2 | ||
Les Tseppes Checkpoint | 148.0 | 1,936 m | — | ||
Vallorcine Aid Station | 155.3 | 1,260 m | 40h30m12:15 PM +2 | ||
La Flégère Aid Station | 166.6 | 1,883 m | 44h3:45 PM +2 | ||
Chamonix Finish | 174.0 | 1,036 m | 45h45m5:30 PM +2 |
Aid station details for this race are still being filled in. Cutoffs and access rules come from the race’s own published information and can change — check the official race details before planning around them.
Sign in for race-day weather at every station, points of interest, segment-by-segment analysis, pacing, and to save this race to your calendar.
Runners may not take part with a dog or any other animal, including service animals.
Late August around Mont-Blanc can bring anything. The valleys (Chamonix about 1,035 m, Courmayeur about 1,220 m) often see 20–30 °C days, while the passes above 2,000 m can drop below freezing at night, and the organizers warn of temperatures down to −10 °C, with rain, hail or snow possible. Afternoon thunderstorms are common, and weather can force course changes or delays. In 2026 the UTMB start was pushed back two hours and the course was adjusted.
Nights above 2,000 m can fall below freezing; warm layers, beanie and gloves are mandatory
Afternoon storms on exposed passes (Col de la Seigne, Grand Col Ferret)
Hot valleys and cold, wet passes on the same day; the organizers can activate extra mandatory gear up to 24 h before the start
![Video thumbnail: [UTMB 2025] Marine Quintard et Mathis Dumas : retour sur la MCC](https://img.youtube.com/vi/k1jWtpkQ6aA/hqdefault.jpg)
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