The Thornapple River, less than an hour from Kalamazoo, is one of my favorites. It's an easy river to paddle with shallow water and plenty of woods and wildlife.
Our paddle from Charlton Park to Hastings took around two hours on a beautiful Sunday afternoon with turtles sunning on logs and cedar waxwings flying overhead. The river was wide and slow at Charlton Park, since it's the end of Thornapple Lake. Downstream, past the cottages, the river narrows and you can drift with the current between wooded banks. That section was popular for innertube floats. We did pass several groups on the river, but it was only crowded in one short section.
Canoes, kayaks, and innertubes are available from U-Rent-Em Canoe Livery 805 W. Apple St. Hastings, Michigan 49058 (269)945-3191
I teach economics at Kalamazoo College. My wife is also an economist. We were on sabbatical in Europe for the 2014-15 academic year. (Salamanca, Spain, followed by Oxford, UK.) We were in Uruguay for the 2006-7 academic year.