The , known as the in its upper reaches, is the longest and widest river in Japan and the third largest by basin area (behind the Tone River and Ishikari River). It is located in northeastern Honshu, rising in the Japanese Alps and flowing generally northeast through Nagano and Niigata Prefectures before emptying into the Sea of Japan. History The Shinano River has a long history in Honshu, and along with other rivers in the region, has a significant effect on the geography and ecology of the area. Originally the Shinano River would have drained straight into an estuary-like Fukushima lagoon before making its way into the Sea of Japan after flowing down from the Japanese Alps. Over centuries of sediments being brought downstream, a marshy plain formed in the lagoon into what is currently the Echigo Plain. Estimates presented in 1993 place the amount of loose sediment in the river system at . The construction of diversion channels have limited the upkeep required to keep a navigable passage between the Niigata port and the open ocean; however, a consequence of diverting sediment has been that the northern coast of Niigata Prefecture (which includes Niigata and its port) is receding by an average per year (measured from 1947 to 1975) due to sediment being released well-south of the river's original mouth in Niigata. The Shinano River Project, funded by the British Academy, investigates the development of the Shinano—Chikuma River system. It has uncovered some of the earliest examples of Flame-style pottery (kaen doki), dating from the Middle Jōmon period (3500–2500 BCE), have been found at Sanka excavation site in Nagaoka, Niigata, near the confluence of the Sai and Shinano Rivers. As with rivers across the world, the Shinano provided a valuable means of transport. The system also provided a method of transport for goods to be moved downstream to one of three ports, Nutaru, Niigata and the provincial port of Kambara. Little evidence remains which details the importance or role of these ports; however, large amounts of Medieval Chinese artefacts have been found in the region, and the Muromachi period play, Miuri, was set in Kambara, indicating its regional significance. There is limited evidence which has caused some historians (such as Shishi Tokamachi) to suggest that the Shinano system was not widely used for boat travel until the eighteenth century. Brian Goldsmith, however, contends that the Shinano was, in fact,