The River Wharfe is a river in Yorkshire, England. For much of its length it is the county boundary between West Yorkshire and North Yorkshire. The name Wharfe is Celtic and means "twisting, winding". The valley of the River Wharfe is known as Wharfedale. The river source is at Beckermonds, Langstrothdale in the Yorkshire Dales National Park and flows through Kettlewell, Grassington, Bolton Abbey, Addingham, Ilkley, Burley-in-Wharfedale, Otley, Wetherby and Tadcaster.