This walk, from Marsden to Black Hill and back, takes both the modern route and the original route for the Pennine Way and is one of the hardest walks in the area covering some of the roughest and boggiest ground in the Peak. This is especially true of the outward journey described - Black Moss, White Moss and the north-west side of Black Hill are all extremely boggy and the best time to walk here is in a period of drought or after a very hard frost. In fact, you could define a masochist as someone who does this walk after a long period of heavy rain or in melting snow!
About 300 metres past Blakeley Reservoir a path by a broken signpost branches off right and drops down to the stream. This is the modern northward route of the Pennine Way from Marsden. Take this path and cross the stream by a small footbridge and then climb the steep bank on the other side. At the top a Water Board path contours to the right around the hillside to the next stream - follow this, cross the stream and follow the well-trodden path alongside the stream, heading uphill.
The path heads initially north-west, curving round to west, and climbs steadily up onto the moor above. After about a kilometre the small reservoirs of Swellands and Black Moss come into view and the path swings right to converge on Black Moss reservoir, crossing several deep groughs before following the south side of the reservoir to the dam.
Here the Pennine Way turns right and heads north to Standedge but a path comes in from your left which is the original Pennine Way route along the watershed from Black Hill, before the line was changed to the Wessenden valley. Turn left and follow this path up onto Black Moss, heading up a series of shallow groughs and peaty ground. Continue over Black Moss and then descend slightly into the headwaters of one of the Wessenden stream systems before climbing up onto White Moss. The ground here is very heavy and there are numerous peat-filled groughs to cross but the path is well-trodden and marked by a series of small cairns.
White Moss was probably the worst section of the whole Pennine Way. An almost level plateau with poor drainage, it is always heavy going and can be a quagmire. Beech fencing has been laid on the path to help combat erosion and stop walkers disappearing into the bog, but it is quite broken and of only limited value so after nearly two kilometres of this fun it's a relief to arrive at the Greenfield-Holmfirth road, the A635.
Turn left and walk along the road eastwards for perhaps 200 metres. A path then heads off south-east past a small quarry and crosses Wessenden Head Moor towards Black Hill. It is unmarked and not always easy to follow - there is a line of stakes but these are a red herring, so ignore them. The route starts on a bearing of 130 degrees, swinging round to 110 degrees after a few hundred metres, and crosses 2 kilometres of very boggy ground before arriving at the foot of the slope leading up to Black Hill. Only White Moss can beat this stretch, and the path is more difficult to follow here.
To descend the hill you want to come down the western edge of Issue Clough. Once again this is not easy to find in poor visibility and there are several faint paths to mislead you, though now much of the path near the summit is paved. If necessary, take a bearing of 30 degrees and if you don't find the right path then continue along this bearing. Be careful - another track starts off on a bearing of 50 degrees but this ends up at Holme Moss!
The edge of the plateau near Issue Clough is marked by a large cairn which can be seen below from miles away. This is the modern line of the Pennine Way so the path is well-marked from here and leads down the shoulder on the west side of the clough before turning left to follow a drainage ditch which contours around the hillside. After a short distance it becomes paved and crosses several small streams before making a sharp descent to cross Dean Clough. You climb out of this and up the hillside to be re-united with the A635 near the site of the old Isle of Skye Inn.
Depending upon the direction from which you arrive, this walk can be started from the A635, either at the White Moss end or at the Marsden road - and there are car parks at both these points. It is also possible to split the walk into either of two halves, but you then have the problem of a 3 kilometre walk along the A635 to return to your starting point.