The Shinano River is Japan's longest and one its best known rivers.The Shinano River is also called the Chikuma River on the Nagano prefecture side. Its source is at Kobushi-ga-dake located around the border between Nagano, Saitama and Yamanashi prefectures. It runs through both Niigata and Nagano prefectures and flows into the Sea of Japan.
The Shinano River has repeatedly burst its bank in the past, flooding the basin and causing severe destruction. For the efforts of people symbolized by the Ohkouzu Diversion Channel, the Shinano River has now left its basin rich and fertile, and contributed to the region's development.