The primary tributary of the river is Clark Brook, which rises south of Mount Cardigan in the town of Alexandria and drops over Welton Falls. Chesley Brook joins from the north, at which point the stream valley widens and begins to support small agricultural operations. The brook's name changes to "Fowler River" when Brock Brook joins from the right at the first crossing of Fowler River Road. The river flows southeast to a junction with Bog Brook, where it turns north and flows one mile to Newfound Lake.
