BikerBoy from Edwardsville, IL on 3/12/2012 1:14:24 PM:
I think the only safe way to do it is to ride along MO-94 to West Alton then to Alton and cross the Clark Bridge, then head south on the MCT Confluence Trail, which is on top of the levee. That takes you right down to the Chain of Rocks bridge. Just be careful along MO-94, as indicated in other posts here, the locals are very comfortable driving fast and the shoulder is narrow.