Grand Trail du Lac

The Grand Trail du Lac is a spectacular autumn mountain running event held around France’s largest natural lake, Lac du Bourget, located about a half hour from Annecy, France and one hour from Geneva, Switzerland. It offers three main race formats, each showcasing rugged trails, lakeside panoramas, and alpine ridge running and departing from with Le Bourget-du-Lac or Chanaz during the Festival International du Trail.

The flagship 74 km solo loop circumnavigates the entire lake from Le Bourget-du-Lac, starting before dawn. This course blends nocturnal sunrise beauty with varied terrain and mountain-crest views as runners tackle 3,600 meters of ascent across rolling single-tracks and steep ridge climbs.

The 74 km relay shares the same full-lake route but splits it into four legs – 21.6 km (890 m+), 14.4 km (515 m+), 22.4 km (1,185 m+), and 15.1 km (990 m+) – allowing teams of four to experience the course’s toughest ascents and technical descents in manageable stages.

For those seeking a shorter yet still demanding challenge, the 34 km solo event begins in Chanaz, a village on the north end of the lake. It covers roughly 1,978 meters of climbing across about 80% single-track, with key highlights including the ascent to and then under the Dent du Chat.

All races offer multiple aid stations, rugged trails, and scenic variety – from lakeshore trails to alpine ridges – with views of Mont Blanc and the surrounding massifs.