The race goes through routes in Courmayeur, Pre Saint- Didier and la Thuille for a total length of about 90km and an altitude range of 6000mt, mainly going along Val Veny and Val Ferret. Start and finishing lines in Courmayeur. About 60km and 4000mt of altitude range from the start, the race goes through downtown Courmayeur again; there runners can stop in a refreshment point and have an hot meal. Runners must complete the route in 26 hours. The race is technical, due to the high altitude range but the routes it develops on are not particularly tricky. Passages on sealed roads are reduced to the minimum possibile: the race will use them just around town where it crosses public streets.