The Sarufutsu River is nationally famous as the habitat of Japan's largest freshwater fish, the Itou, which has become a symbol of the village. The river originates in the Kamisarufutsu area and flows north to south through the mountains and magnificent marshlands, flowing into the Sea of Okhotsk through a series of large and small tributaries and swamps. The middle and upper reaches of the river are almost untouched by human hands, and many precious primitive streams remain.