UTMB
4 letters. 3 countries crossed. 1 extraordinary adventure, which is now the 100M finals of the UTMB World Series. This is the iconic race that has taken so many passionate runners on an extraordinary journey around the Mont-Blanc.
Race Category
UTMB 2025: course information
UTMB start time: 17:45 – 174km and 9,900m of elevation gain
Due to recent rockfalls between Chamonix and Les Houches, this section of the course has been reworked. Following several on-site assessments, an alternative route has been chosen that ensures runner safety while staying true to the spirit of the original trail.
As a result, the final UTMB course will now cover 174km with 9,900m of elevation gain.
What’s changing:
- A new route between Chamonix and Les Houches,
- A 15-minute earlier start time: Friday 29 August at 17:45, still from Place du Triangle de l’Amitié.
There is no change to the cut-off times — this page has all the latest details including the updated route map, estimated split times and elevation profile.
THE ULTIMATE REFERENCE IN TRAIL RUNNING
Created in 2003, the UTMB is "the most mythical and prestigious trail running race in the world" with 171 kilometers and 10,000 meters of positive elevation gain around the Mont-Blanc through Italy, Switzerland and France. A race like no other, it transcends the sport, and has established itself as an iconic trail race, renowned worldwide.
No matter the time it takes to finish, whether done in under 20 hours or more than 46, the elite runners as well as amateur runners share the same adventure on the same exceptional course, carried by the stunning beauty of the landscapes and a common goal: to cross the finish line in Chamonix. Much more than a race, it is an introspective adventure which transforms every person that takes on the challenge.
Note: The course (distance and elevation gain) may be adjusted depending on terrain constraints.
A closer look at the course
We have gathered all the practical information to answer your questions about your race. Check out this section to learn more about bib pickup, transportation, mandatory equipment, and more.
