Grand Duc - Trail de Chartreuse

The Grand Duc -- Trail de Chartreuse is the flagship ultra-trail of the Chartreuse massif, a 72-kilometer race with 4,200 meters of elevation gain that winds through this unique pre-Alpine range, renowned for its vertiginous limestone cliffs, deep forests, and the Grande Chartreuse monastery, cradle of the Carthusian order. Starting from Entremont-le-Vieux, a characterful village in the heart of the Chartreuse Regional Natural Park, this June race offers a total immersion in a massif with a strong personality, midway between Grenoble and Chambery.

The Chartreuse massif is a world apart in the Alps. Its limestone cliffs, forming vertical ramparts several hundred meters high, enclose narrow valleys covered in dense forests of beech, fir, and spruce. The atmosphere is dark, humid, almost mystical. Grand Duc runners move through this impressive setting, alternating between moss-carpeted forest trails, passages beneath cliffs where water seeps constantly, and summit ridges offering commanding views of the Northern Alps. Le Granier (1,933 m), the Dent de Crolles (2,062 m), and Chamechaude (2,082 m), the highest point in the massif, are the limestone sentinels that dominate the course.

The distinctive feature of Chartreuse terrain lies in its karstic character. Limestone, eroded by millennia of rain, has created an underground network of caves and sinkholes that makes the surface terrain unpredictable. Lapiaz formations -- bare rock surfaces scored with channels -- appear regularly on the ridges and demand careful progression. Passages beneath cliffs, through grassy corridors called cheminements, can be exposed and technical, with slopes exceeding 40% where hands are necessary. Limestone rock, extremely slippery when wet, requires shoes with appropriate grip and constant vigilance.

Chartreuse is also a territory of spirituality and silence. The Grande Chartreuse monastery, founded in 1084 by Saint Bruno, is still inhabited by a community of Carthusian monks living in near-total isolation. Though the monastery itself is not open to the public, its presence imbues the entire massif with an atmosphere of contemplation. Runners cross forests where silence is almost palpable, broken only by birdsong and the murmur of mountain streams. Summit pastures, where cows graze to produce the local Entremont cheese, offer moments of pastoral serenity that contrast with the intensity of the climbs.

The Grand Duc is accessible to runners with solid mountain trail experience, without requiring the technical background of a high-altitude Alpine ultra. The 4,200 meters of elevation gain over 72 kilometers is sustained, and climbs are often steep and direct. As Chartreuse is one of the wettest massifs in the Alps, rain is frequent and mud virtually guaranteed on certain forest sections. Equipment should prioritize waterproofing and warmth, even in June when forest temperatures can remain cool. The race takes place largely in forest, which limits sun exposure but can create a feeling of forest enclosure over long stretches. The Grand Duc is a race of atmosphere, an immersive experience in one of the most secretive and enchanting massifs in the French Alps.

Grand Duc - Trail de Chartreuse is a 72 km trail race with 4,200 m of elevation gain, located in Entremont-le-Vieux, Isère. The next edition is scheduled for 28 June 2026.

Find all official information on the race website.