Overview

• About 2,500 runners departed Chamonix on a 174 km loop with more than 9,900 m of elevation gain around Mont‑Blanc.
• Rockfalls between Chamonix and Les Houches forced a course detour of roughly 3 km, with leaders projected to hit Courmayeur around 02:30, Champex near 08:20, and Vallorcine about 11:30.
• Large segments will be run overnight by headlamp, including key mountain terrain such as the Col du Bonhomme encountered at dusk.
• Forecasts call for clouds and rain overnight with temperatures below 10°C, turning milder near 21°C on Saturday before showers return on Sunday.
• Four‑time winner François d’Haene headlines the men’s contenders alongside Jonathan Albon, Ben Dhiman, Hayden Hawks, Jeff Mogavero, Daniel Jones and Ji Duo, while Courtney Dauwalter leads the women’s field; live coverage streams on UTMB’s YouTube channel and L’Équipe.