This isn't a route, but it gives info for every state.
http://byways.org/explore/byways/2279I rode it from Middle Illinois to Fulton, IL. I've been in a a cage from Fulton up into Wisconsin. I'd avoid the IL side anywhere South of the Quad Cities. Some sections are not well marked and don't follow the river nearly as close as you'd think. On the Iowa side heading South from Clintom to South of Hannibal , MO was a nice stretch. I especially would detour at Dubuque, IA to find the Field of Dreams. Bellevue has a nnice restaurant called the Offshore that overlooks the river. Clinton (my hometown) has a few nice places to eat, but Rastrelli's is my favorite, and first paying job I ever had. Davenport has nice riverfront shopping too. Hannibal was cool because you can see all the sites that inspired Tom Sawyer & Huck Finn novels by Mark Twain.