Lake Shumarinai

Lake Shumarinai is a reservoir in northern Hokkaido with thirteen islands scattered across its irregular water surface. The shoreline winds into several bays that resemble narrow fjords, giving the water a jagged outline.

The dam was built between 1937 and 1943 to generate power for growing industry across Hokkaido. Flooding transformed the valley into a sprawling water basin with branching arms.

The name comes from an Ainu word referring to the shape of the original riverbed before the basin formed. Anglers from the area visit in winter to fish through thick ice layers, sitting quietly over the frozen surface.

The area works best for visits from spring through autumn when roads remain snow-free and weather stays calm. In winter the surface turns into a thick layer of ice that makes boat fishing impossible.

The basin shelters taimen that take decades to reach full size. These rare fish live in cold, clean depths and belong to the oldest salmonids in the world.

Location: 幌加内町

GPS coordinates: 44.31750,142.20722

Latest update: December 19, 2025 22:20