The KalHaven trail runs on the right-of-way of the old Kalamazoo & South Haven Railroad. Officially a state park, the Kal-Haven trail is currently operated by Van Buren County. The trail runs for 34 miles from the 10th Street caboose to South Haven. The Kalamazoo Valley River Trail connects the Kal-Haven trail to downtown Kalamazoo (and will eventually extend to Battle Creek.)
The trail is crushed limestone, smooth enough for all but the skinniest of bike tires. The hills aren't steep since the entire route was graded for railroads, which makes for long-gentle downhill runs and subtly tiring uphill returns. In warm months, the shady path attracts lots of bikes. Snowmobiles dominate the trail in Winter. In Spring, it's surprisingly good for wildflowers. It makes a nice walk in any season.
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.