Marathon du Mont-Blanc in 2012, a running event organized in Chamonix (France) from 29 / 30 June. During the 2 races were held event. Marathon du Mont-Blanc (⨦ 42 km / + 2 500 m) in class RMT4 with average terrain slope 6% (G6). Cross du Mont-Blanc (⨦ 23.5 km / + 1 450 m) in class RMT2 with average terrain slope 6% (G6).