The Dowagiac River mainstem is formed by the confluence of the Dowagiac Drain and the Lake of the Woods Drain near the southern edge of Hamilton Township, becoming the Dowagiac River before entering Wayne Township in Cass County.
The Dowagiac River begins its journey as a result of the merging of the Dowagiac Drain and Lake of the Woods Drain near the southern edge of Hamilton Township.  It then flows into Wayne Township in Cass County, becoming the official Dowagiac River.