It rises north of Cleckheaton, runs through Liversedge and flows into the Calder to the south of Dewsbury at Ravensthorpe.

Heavy rain can cause pollutant levels to rise and the river suffers from tipping and urban litter.

[3] Several non-native species of plant are found along the river including giant hogweed, Himalayan balsam and Japanese knotweed.

[4] The disused railway line adjacent to the riverbank is part of the Spen Valley Greenway (National Cycle Route 66) from Dewsbury to Oakenshaw near Bradford.

The greenway is home to a collection of artworks, including A Flock of Swaledale Sheep, constructed from recycled industrial scrap by Sally Matthews, and Rotate by Trudi Entwistle which comprises 40 giant steel hoops set in a circle.