Walk to Illinois

Today, we walked to Illinois & we didn't even get wet! We drove to the 'Chain of Rocks Bridge', which is a mile-long structure that spans the Mississippi River from the northern edge of St Louis to Chouteau island in Madison County, Illinois. This originally carried Route 66 over the Mississippi, but is now used as a walkway (apparently, it is the 2nd longest pedestrian walkway/bridge in the world) & bike trail across the river.

The bridge's name is derived from a rock-ledged reach of river (described as a chain of rocks) which stretches for approximately seven miles immediately to the north of St. Louis. When river levels are lower (the river was still in flood when we walked over it) there is a line of rapids visible just south from the bridge. These are created by water spilling over the 2,925-feet low-water River Dam 27, which was the first permanent rock-fill dam constructed across a major river in the US. This dam was built in 1960 by the US Corps of Engineers to insure adequate water depths over the lower sill of the old Alton Lock that was 12.5 river miles upstream. River-traffic uses the Chain of Rocks canal, which is a 47-mile long man made channel built through Illinois, to bypass this section of the river.

One of the most interesting features of the bridge is that it has a 22-degree bend at mid span. This was needed due to the unique geology of the area & concerns about the navigation of river traffic around the bridge piers. If the bridge had been built straight, one route would have put the bridge in a location where it couldn’t be solidly founded on bedrock & the other route would have posed problems to river navigation by not allowing barges to line up with the current, possibly causing them to collide with the bridge.

Two Gothic castle-like structures stand in the river just to the south of the bridge which are water intakes for the Chain of Rocks Water Treatment Facility. This is located downstream from the bridge & was originally opened in 1894. It is still in operation today, providing potable water to St Louis. You also get some really good views of the St Louis skyline from the bridge, &, apparently, Bald Eagles can sometimes be spotted in the area during colder weather.

The bridge has an interesting past. It was originally constructed as a toll bridge in 1929 at a cost of US $3.0 million. In the late 1930s, Bypass US 66 was designated over this bridge & around the northern & western parts of St Louis to avoid the downtown area (City US 66 continued to cross the Mississippi River over the MacArthur Bridge). Eventually, the toll was removed from the bridge due to a law prohibiting the collecting of tolls on US Highways. In 1967, the New Chain of Rocks bridge was built immediately to the old bridge's north to carry Interstate 270 across the Mississippi. In 1967 the old Chain of Rocks Bridge was closed. The bridge was subsequently leased to Trailnet (which is a local trails group) & US $4.5 million spent renovating the bridge as part of the trails network. The bridge was added to the US National Register of Historic Places in 2006.