Trail'oween 2026

Trail'oween is a late-October trail race held in Les Clayes-sous-Bois, located in the Yvelines region west of Paris. Participants can select a 10 km or 20 km run, with an additional 10 km option for Nordic walking. The race embraces its Halloween timing, encouraging participants to wear costumes, blending a trail run with a local costume party. The Dadoo Run Run association organizes the event in partnership with the town of Les Clayes-sous-Bois. Both running courses are single loops crossing natural and forest landscapes. The 10 km route features 240 metres of elevation gain and attracts the larger field, exceeding 300 finishers in the prior edition. The 20 km route includes up to 500 metres of climbing and saw over 100 participants. The entire event drew close to 600 runners and walkers, selling out despite unpredictable weather. Approximately fifty volunteers contribute to its operation, and the organizers' notes highlight costumes, smiles, support from partners and the town, and post-race volunteer photos.