River Tees

The River Tees rises on the eastern slope of Cross Fell in the North Pennines and flows eastwards for 85 miles to reach the North Sea. Its upper reaches pass through Teesdale, a valley of moorland and hills over 760 metres high, part of the North Pennine Area of Outstanding Natural Beauty. The river’s source lies just below Cross Fell at about 732 metres elevation. It then flows through an area of shake holes in carboniferous limestone before reaching Cow Green Reservoir. Below the reservoir at Cauldron Snout the Tees descends a series of hard basalt and dolerite rocks in falls and rapids. The Tees forms the boundary between historic counties and now separates County Durham from North Yorkshire along much of its course. High Force, a 21-metre waterfall, lies close to the B6277 road. Downstream, Middleton-in-Teesdale is followed by the junction with the River Lune. The river then passes Barnard Castle, Egglestone Abbey and Rokeby Park, which inspired Sir Walter Scott’s poem Rokeby. Near Rokeby the Greta joins the Tees, and the valley opens out across fertile plain east of Darlington. Further downstream the river turns north-east past Ovington and Winston, running parallel to the A67. At Croft-on-Tees the Skerne joins, and the channel narrows as the Tees approaches Yarm. Here the Leven enters before the river reaches Stockton-on-Tees and Middlesbrough. The Tees Barrage marks the tidal limit, and beyond it lies Teesport on reclaimed land. The estuary flats at Seal Sands now form the Teesmouth National Nature Reserve, where common seals have returned after a century’s absence.