Missouri contains the surviving original Route 66 alignment that crosses the Mississippi River.
Historic Route 66 entered Missouri from Illinois at St. Louis, crossing the Mississippi on the Chain of Rocks Bridge. The bridge’s unusual design includes a sharp bend near its western end, making it one of the best-known structures associated with the road.
The Chain of Rocks Bridge opened in 1929 and carried Route 66 traffic until a newer bridge and changing highway alignments diverted vehicles. It is now closed to motor traffic but remains accessible to pedestrians and cyclists. Illinois was Route 66’s eastern starting state, while Kansas had only a short segment; neither contains this surviving Mississippi crossing.