The source of the river is a spring at Up Sydling. It passes the deserted mediaeval village of Elston and is then crossed at a ford by the road from Marrs Cross to Cerne Abbas. It then flows through the village of Sydling St Nicholas and through rural countryside until it goes under Grimstone Viaduct and soon afterwards into the River Frome near Grimstone. The 'valley road' south of the village of Sydling St Nicholas closely follows the river until it reaches Grimstone.
