TDS - Sur les Traces des Ducs de Savoie

The TDS -- Sur les Traces des Ducs de Savoie -- is the wildest and most committed race in the UTMB Mont-Blanc circuit. Spanning 149 kilometers with 9,100 meters of elevation gain, it takes runners into the most remote corners of the Mont-Blanc massif, far from tourist trails, across mountaineering terrain where the mountain dictates the rules. Created in 2008, the TDS quickly earned a reputation as an extreme adventure race, attracting seasoned trail runners seeking an authentic challenge in a vertical, mineral environment.

The race starts in Courmayeur, on the Italian side of Mont-Blanc. The opening kilometers plunge runners into the Val Veny, beneath the Miage Glacier and the seracs of Mont-Blanc. The terrain hardens quickly: the passage over Col du Chapy, followed by the long traverse to Col Malatra (2,925 m), reveals the deeply mountainous nature of this race. Runners navigate barely marked trails through unstable boulder fields, exposed ridges, and persistent snowfields. The landscape is lunar, mineral, and grandiose. They pass glacial lakes of unreal blue, dominated by the south faces of the massif's great walls.

The central section of the TDS crosses the Beaufortain, a lesser-known mid-mountain region of striking beauty. The alpine pastures of the Cormet de Roselend, the dense forests of the Chapieux Valley, and the glacial meltwater streams compose a pastoral tableau that contrasts sharply with the harshness of earlier sections. It is in this stretch that runners find their rhythm, enjoying warm life bases and aid stations where Beaufort cheese reigns supreme. But the respite is short-lived: the Col du Bonhomme (2,329 m) and Col des Fours (2,665 m) serve as a brutal reminder that the TDS never gives anything for free.

The final third of the race follows balcony trails high above the Chamonix Valley. The passage through Les Contamines-Montjoie, then the climb to Col du Tricot with its spectacular suspension bridge over the Bionnassay torrent, provide defining moments. The view of the Dome du Gouter and the Aiguille de Bionnassay, a summit exceeding 4,000 meters, is staggering. The final descent into Chamonix via Les Houches and the Chemin du Merlet offers a complete panorama of the Mont-Blanc range, rewarding the efforts of more than 40 hours of racing for most finishers.

The TDS demands specific preparation and advanced mountain experience. Technical passages are numerous, with cable-equipped sections and fixed handrails where a head for heights is essential. Weather at high altitude can be formidable: fog, violent thunderstorms, and sub-zero temperatures even in August. A complete high-mountain equipment kit is mandatory, including gloves, beanie, Gore-Tex jacket, and emergency blanket. The TDS is not merely a race: it is a mountain expedition compressed into a competitive format, an experience that profoundly marks everyone who lives it.

TDS - Sur les Traces des Ducs de Savoie is a 149 km trail race with 9,100 m of elevation gain, located in Courmayeur, Haute-Savoie. The next edition is scheduled for 26 August 2026.

The course reaches a maximum altitude of 2,665 m. The race is rated 6 ITRA points and features terrain. 1 distances are available for runners.

Find all official information on the race website.