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's main stem originates from the confluence of the Dowagiac Drain and Lake of the Woods Drain near the southern boundary of Hamilton Township, transforming into the Dowagiac River before entering Wayne Township in Cass County.