The Kawkawlin has two main branches, the North Branch, which is the longer branch, and the South Branch, which is also known as simply the Kawkawlin River. The confluence of the north and south branches northwest of Bay City at , just a little more than one mile from the mouth of the river. The North Branch rises from the confluence of Hoffman Drain and Watson Drain at , at the southeast corner of Gladwin County. Upstream from the confluence with the North Branch, the Kawkawlin (or the South Branch), rises from the confluence of Dietline and Betzoid drains at .
