A river where salmon run upstream

The Nishibetsu River is fed by the subsoil water of Lake Mashu.
This clear stream, with white baikamo flowers swaying on the surface of the water, is famous for its big rainbow trout in addition to oshorokoma and landlocked salmon, and is a favorite of fishermen. In Ainu language, it is called "Nuusi Petu" (a river with good catches).