The river's source is Scotia Lake, a small lake east of Halfway Lake Provincial Park in Sudbury District. From there, it flows north and east, taking in two small tributaries and continuing to a point 20 kilometres southwest of the Ishpatina Ridge, where it turns south. After approximately 60 kilometres, the river flows into Lake Wanapitei in the northeastern portion of Greater Sudbury. At the south end of the lake, the river continues, flowing south until it joins the French River near the latter's mouth on Georgian Bay on Lake Huron. The river is approximately in length and is a popular wilderness canoeing route.