If you decide on your first route, you can use the Great River Trail maps to go from Chester north to Grafton. A lot of it will be on bike specific trails which is great, but unfortunately you must pass thru East St. Louis which is not so great. Be careful there. If you don't want to go that far north, consider the Chain of Rocks bridge as it is really neat and is bicycle and pedestrian only. You can then make your way up north to St. Charles and the trailhead as St. Louis is a fairly friendly bicycling city. The photo below on the Chain of Rocks this past season.

edit Link to Illinois Mississippi trail

http://www.bikelib.org/wp-content/up...ideBooklet.pdf