 The Skerne is about long and begins in Magnesian Limestone hills between Trimdon and Trimdon Grange and ends at Hurworth Place where it joins the River Tees.Three miles after the source the Skerne is joined by Hurworth Burn and enters Hurworth Burn Reservoir on the borders of Stockton-on-Tees and County Durham.On leaving the reservoir, the Skerne heads south-west towards Sedgefield.