Jill and I went to Yorkville Illinois last week to paddle the whitewater park (see youtube). It is an excellent class 1 1/2 or 2 facility to play and learn swift river and whitewater skills. I submitted a destination report to paddling.net .
If you liked Yorkville, try some of the Iowa parks. Manchester and Charles City are a lot of fun. I didn’t make Elkader on my Iowa tour, but hear it can be good at certain levels too.