The river rises in the region of Bergisches Land in the municipality of Reichshof.

Its source is located about 700 metres north of the village of Hahn on the southern slopes of the Silberkuhle (514.6 m) at a height of 446 m above sea level (NHN).

After passing Brüchermühle it is impounded again, this time by the Stauweiher Bieberstein.

After passing through the parishes of Oberwiehl, Wiehl, Bielstein and Weiershagen, it empties into the Agger near Wiehlmünden at a height of 145 m above NHN.

On 3 May 2001, following torrential rain, what were described as hundred-year floods washed away parts of some roads.