The Winter Trail Réallon begins at the Réallon ski resort's snow front, situated in the Hautes-Alpes region between the Écrins massif and Lake Serre-Ponçon. This semi-nocturnal winter trail race takes place on snow, with participants starting in the early evening using headlamps. The event features two primary distances: Fond Renarde, approximately 9 km with around 300 m of elevation gain, and Serre Mouton, about 14 km with roughly 550 m of elevation gain. It welcomes experienced trail runners and those seeking a brief, intense mountain race during winter.
The courses traverse snowy forest paths, larch woods, ridgelines, ski-area tracks, and trails within the Réallon valley. Fond Renarde departs from the resort towards the valley's edge, then circles back via the Vaucluse piste and the Oiseaux trail before descending to the resort. Participants must wear trail shoes equipped with anti-skid chains, and carry a headlamp, survival blanket, water, and a mobile phone. Action 05 and Chorges Trail Club are the organizers, supported by local volunteers. Upon finishing, runners receive refreshments, including mulled wine or a soft drink, and can pre-order croziflette for themselves and guests during registration.