Trough of Bowland

The pass, reaching 968 ft (295 m) above sea level at the head of the valley, links to Wyresdale, dividing the upland core of Bowland into two main blocks.

[1] The Grey Stone of Trough, at the head of the pass, marks the line of the historic county boundary between Lancashire and the West Riding of Yorkshire.

However, the generally used definition includes: The Trough is very sparsely populated: there are only two farms on the Langden side (Sykes and Hareden), and, in Wyresdale, the small community of Marshaw.

What is believed to be the former location of the Sykes Smelt Mill is now the headquarters of the Bowland Pennine Mountain Rescue Team.

Water intakes were built at the mouths of Hareden, Losterdale and Langden Brooks in the 1920s, linked by a series of aqueducts to the Alston Reservoirs near Longridge.