[1] The lake formed when the Akan River was dammed by an eruption of Mount Oakan some 6000 years ago.

[2][3] The river exits the lake at Takiguchi as a waterfall.

This spot and Takimi Bridge nearby are attractions in Akan National Park.

[3] The river winds its way south entirely within the district managed by Kushiro, Hokkaidō.

The river then flows into the Pacific Ocean.