I did 5 years in Chicago and, believe it or not, there is quite a bit of paddling there (well, within a few hours drive).
Lake Michigan is actually where I learned how to paddle. When the lake level was higher there were actual waves during the winter (10-12 foot faces) if you don't mind surfing with ice chunks.
That sounds unpleasant doesn't it. It is not all that bad. There is the Wolf River which has some fun play sections (4 hours away), the nearby Peshtigo which has the most fun play. Piers Gorge on the Menominee is good Midwest Class IV. And there is gnar runoff into Superior in the Spring. As hairy as you want it. Oh yeah, and East Race, an old slalom training thing in Indiana. Never went.
Here is the other part that people forget. The East Coast is a heck of a lot closer than it is to CO. W. Virginia is around 9 hours from Chicago and Tennessee is about the same I think. If you're not afraid of driving, there are pleanty of diehard weekend warriors there.
It's a fun town. Lots of young attractive people and a bar on every corner. Try it for a while but be prepared to drive if you want to paddle.
Post on
http://www.phateye.com - quite a few midwestern paddlers there.