Grand Trail de la Vallée d'Ossau

The Grand Trail de la Vallée d'Ossau is a mountain trail race held in Laruns, located in the Pyrénées-Atlantiques department of southwest France. It takes place in early July, offering race options ranging from the 25 km TVO to the 74 km GTVO, available in solo and relay formats. The extended solo race is integrated into the UTMB Index system, covering approximately 72 km with 4,600 meters of elevation gain, presenting a demanding Pyrenean challenge rather than a simple forest run. The primary 74 km route forms a single loop, guiding participants through a circuit of the Ossau valley's landscape before concluding back in Laruns. The event emphasizes mountain, nature, and high-altitude running. The relay format allows teams to share the full-distance course, accommodating participants who prefer not to undertake the entire ultrarunning distance solo. The 74 km race attracts a substantial field, with over 500 participants registered for that distance in the most recent edition and 449 solo finishers recorded.