From the start at Ashworth Moor Reservoir, one of many created in this area to serve the nearby towns, the walk sets out on one of the large number of paths and tracks criss-crossing the moors, to reach Wolstenholme Fold, a collection of cottages and farms typical of the West Pennines. This was once home to a community of farmer-weavers, who supplied part finished cloth to the small mills in the narrow valleys here. The remains of two of the mills can be found in the valley of Naden Brook. Part of the facade of Ashworth Mill stands in a gloomy wooded hollow below a weir.

In the neighbouring valley of Cheesden Brook are more remains. Kershaw Bridge Mill, founded in 1780, was the first mill recorded in the valley. It produced fustian, a hard-wearing mix of cotton and linen. The mill closed towards the end of the 19th century.

Birtle Dean Mill stood further upstream, in a great natural ampitheatre. Built in 1824, this substantial mill, the valley's largest, took in new cotton and produced dyed finished cloth. Terraces of houses were built for the workers. The mill lasted for less than eighty years; today only a few slabs and stones remain. On hot summer days these are occupied by lizards and slow worms, basking in the heat.

Beyond Birtle Dean, the valley loses its thick cover of trees and the valley widens out. The walk winds past shale terraces that mark the site of one of the several mines in the valley. These were developed to produce coal for the steam engines that augmented or replaced the earliest of the mills water wheels.

Further on, you pass a chimney stack at Lower Wheel, where there was once a bleaching works. The wide valley floor here is home to large numbers of rabbits, easy prey for the foxes and buzzards that you may see here. Mountain Hares adorned in their white fur of the cold season are also known to be frequenting the valley, seeking shelter from the harsh high moor winds.

The ruins of Deeply Vale, a calico printing works which later produced paper, are more substantial than most: moss covered, cobbled roads wind in and out of the woodland; walls covered by ivy and ferns stand against the ravages of nature and vandals; and old, rust stained wheel pits host large trees. The dam holds back a large millpond, now fringed by reeds and a favourite haunt of herons, coots and brightly coloured dragonflies. In the 1970's the site of Deeply Vale was the unlikely setting for a series of outdoor pop festivals, attracting performers such as Steve Hillage and the Fall. Ending the run in 1979 the festival was briefly revived in 2015 and again in 2016.

For about the next mile, the only reminders of the half dozen or so mills that once thrived here are a couple of dark, brooding ponds, an occasional piece of masonry or cobbled path and the breached dams of several more millponds. Looking west from the dam at Longlands, there is a fine view of Peel Tower above Ramsbottom and of the distant Winter Hill above Bolton.

Across the top of the narrow valley stretches the impressive facade of Cheesden Lumb Lower Mill. This old wool mill was badly damaged by a storm in 1990, but work since, funded by English Heritage, has led to its partial restoration.