A good salmon and sea trout river, it rises between Baysdale and Westerdale in an area known as Esklets (251 m above sea level).
Its 28 mile (45 km) course sees it flow through the North York Moors National Park to its eventual meeting with the North Sea in Whitby. A small and tree lined river, it offers a source of great protection to all its fish species. Very much a "spate" river and tends to fish well after a good spate. Seatrout are in good numbers in the river and it also get a run of salmon during the summer. Best Months for fishing are May-September.
The river is approximately 119 km long from its source to the point where it changes name to the River Ouse. It is the principal river of Wensleydale, which is the only one of the Dales now named after a village rather than its river. With the introduction of the salmon hatchery, the river is becoming more sought after for its salmon and continues to be a great success. The river also offers good trout fishing during the late spring and summer months.