File:Sheepfold in Crawlaw Gill - geograph.org.uk - 1567850.jpg

English: Sheepfold in Crawlaw Gill This beck is a superb example of stream capture, and also unusual in having no less than four different names in a short distance, whilst the stream whose headwaters were captured has itself three different names. Starting on the moors as Yoke Sike, it becomes Crawlaw Beck and then, as it cuts down to the north of Slates Hill, Slateshill Gill. This once formed the upper reaches of what now appear as Duck Sike, which in turn becomes Yawd Sike and eventually How Beck. To the north, Hunder Beck had a bigger catchment, and cut down more quickly, dropping northwards into Baldersdale. A tributary stream at the point where Hunder Beck turned north was rejuvenated and cut back by a process of headward erosion until it captured the headwaters of How Sike. This stream is now Crawlaw Gill, shown in the photograph, taken from just above the point of this first capture. The process continued until the head of what had been How Sike captured the stream that is now Slateshill Gill. The result is a deeply incised valley in which water, initially heading east, abruptly turns north, then, 400m later, equally suddenly turns back west, until at the confluence with Hunder Beck, it heads north again. It is likely that Hunder Beck and Mawmon Sike were themselves earlier captured by a more rapid downcutting of the Balder valley, though evidence for this is a lot less obvious now. The deep incision of these valleys provides a good sheltered spot for the sheepfold on a generally wet and windswept moorland area.