La Grande Odyssée Savoie-Mont-Blanc
La Grande Odyssée Savoie-Mont-Blanc is intended for mushers with teams of 14 dogs who are experienced in long- and middle-distance. Through Savoie and Haute Savoie, France and Switzerland, mushers from perhaps a dozen different countries, compete for two weeks of racing over a course more than 800 km long, with a change in altitude of more than 25,000 metres (82,000 ft).
The course takes the teams to 24 ski resorts (20 French and four Swiss). For each of the 10 stages, time-trialed (every two minutes) or mass (in parallel) starts bring thousands of spectators to the Savoie-Mont-Blanc region. The race includes three completely independent encampments: one in the first week and two in the second week (Wikipedia)