The Ouse is a river in Eastern England. It is a tributary of the Humber Estuary and flows through the counties of North Yorkshire, Cambridgeshire and Bedfordshire. The source of the Ouse is in the Yorkshire Dales National Park and it flows for approximately 115 miles before joining the Humber Estuary. The Ouse is an important waterway for navigation and has been used for centuries to transport goods and people.