第32回四万十川ウルトラマラソン 2026

The Shimanto River Ultra Marathon is an October ultramarathon in Kochi Prefecture, run beside the Shimanto River, often called Japan's last clear stream. Runners choose between two long-distance divisions, 100 km or 60 km, so the event is built for people ready to spend many hours on the road rather than a standard city marathon crowd. The course follows the river closely enough for runners to feel its flow and passes Shimanto's chinka-bashi, the low submersible bridges that sit almost level with the water. The race leans heavily on local volunteer support, and the organizers also use Japan's Furusato Nozei hometown tax donation system to help fund outsourced work that would otherwise fall on volunteers.