This was the route I took. I was pressed for time and didn't have the extra time for the additional 10 miles that re-routing back thru Illinois takes using Jerry's route. Unfortunately the Chain of Rocks bridge was closed the day I came thru which made my choice even more fortuitous. It makes full use of the St. Louis River Road trail which is really a nice ride.

https://ridewithgps.com/routes/12321040