High Force

High Force is a waterfall on the River Tees, near Middleton-in-Teesdale, Teesdale, England. The waterfall is within the North Pennines Area of Outstanding Natural Beauty (AONB) and the European Geopark. The waterfall is part of the historic county boundary between the North Riding of Yorkshire on the south bank, and County Durham on the north bank (however, since the local government reforms of 1974, the south bank of the Tees in Teesdale has also been included within County Durham for administrative purposes).

The whole of the River Tees plunges 70 feet (21 m) over a precipice (an almost vertical cliff edge) in two stages. After heavy rainfall the river will also flow over the usually dry right-hand side channel, creating two falls. Very occasionally the river level will be high enough to flow over the central section of rock; the last recorded time this happened was in December 2015 after Storm Desmond. In harsh winters the falls have been known to freeze, creating cathedral-like ice formations.

Access to the northern bank is via a private footpath on the Raby estate for which a fee is charged. The southern bank can be reached free of charge via the Pennine Way public footpath which crosses the Moor House-Upper Teesdale National Nature Reserve.