The UTMB or Ultra Trail du Mont Blanc, is Chamonix's biggest trail running event and is renowned the world over for its incredibly long and challening races.
The event attracts around 8,000 ultra-marathon and endurance trail runners from no less than 87 different countries to compete in 5 gruelling mountain trail races.
2017 sees the event going into its 15th year and the organisers have introduced a couple of new features to keep spectators, supporters and runners up to date with lots of live data and even more information than ever before. They've also released the programme for this year's event.
Live interface for spectators
Live information for supoprters
New App for runners
The UTMB Races & Start Times
The 2017 Programme
Location: Chamonix / Mont Blanc Valley
Event: Races / Competition | Sports Event