Yorkshire River Derwent

The Yorkshire Derwent rises at Lilla Rigg on Fylingdales Moor (North York Moors) the only river of the eastern moors, running south east across the moors towards the coast.

The river changes in character more than most moorland rivers. The upper reaches flow between the northern end of Langdale Forest and the open moors. After four miles the river turns south and runs through Langdale (a valley), with the narrow ridge of Langdale Rigg to the west and the steep slopes of Broxa Forest to the east.

After emerging from Langdale the Derwent meanders its way through an area of more open farmland, bounded by steep sided but more distant hills. Originally this was the last stretch of the river, and it ran into the sea just to the north of Scarborough.

This all changed during the last ice age, towards the end of which the glaciers retreated at different speeds, with the thinner glaciers over the Moors melting more quickly than those over the modern North Sea. As a result the Derwent was unable to flow into the sea and a large lake built up to the north of the Tabular Hills. Eventually this lake overflowed the hills penning it in. The resulting flood carved out Forge Valley.

The Derwent still flows down the Forge Valley, emerging form the moors between West and East Ayton. At this point the river is only four miles from the coast, but it turns its back to the sea and flows west across the Vale of Pickering. The total length of the Derwent is approximately 71 miles (113km). It joins the River Ouse near Barmby on Marsh in East Yorkshire.

The name was recorded by Bede in the 8th century as Deruuentionis fluvii, from the Celtic “river where oak trees grow abundantly".