Peak District National Park

The western extremity of the Calder catchment lies within England's first national park. The Pennine moors fall within the jurisdiction of the Park Planning Authority and the land is subject to strict regulations designed to conserve and protect the area.

The highest point above Holmfirth is Black Hill which stands above the village of Holme with the Holme Moss television transmitter nearby. From here the northern most moors of the national park extend as far as Marsden at the head of the Colne valley. This is bleak country with thousands of acres of peat. The ancient woodlands which once colonised the uplands have long since been cleared, with pollen analysis showing that the forest disappeared as hunter-gatherers settled to farm about 3000 years BC. The peat has built up because the cold, wet conditions prevent proper decay of the vegetation. It acts as a giant sponge at the head of the Colne and Holme Valleys, slowly releasing its water into narrow channels, and gulleys known as groughs. Peat is acidic and it imparts this character to the water which flows down into the Calder.

This barren landscape of bogs and moor is the result of environmental degradation by early humans but is now conserved as an example of wilderness landscape.