| McKinley Bridge - 1926-1929 Municipal Bridge - 1929-1932 Chain of Rocks Bridge - 1936-1966 MLK Bridge - 1966-1977 |
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| McKinley Bridge - 1926-1929 Municipal Bridge - 1929-1932 Chain of Rocks Bridge - 1936-1966 MLK Bridge - 1966-1977 |
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McKinley Bridge
The original alignment in St. Louis entered Missouri on the McKinley Bridge in St. Louis and continued west on Salisbury Street, turned south on Florissant Street, then west on Manchester Road (Missouri 100). It joined the later alignment at Gray Summit. The McKinley Bridge is a steel truss bridge 6,313 feet in total length. It was constructed in 1910 and taken out of service in the early 2001. It reopened for vehicular traffic in late 2007.
Municipal Bridge
In 1929, traffic was shifted to the Municipal Bridge (renamed the MacArthur Bridge in 1942 in honor of General Douglas MacArthur). The bridge carried both railroad and vehicular traffic across the Mississippi River for decades. The roadway on the upper deck was closed in 1981 due to the high cost of renovation and repair. The railroad on the lower deck remains in use today.
Chain of Rocks Bridge
Bypass US 66 was routed over the Mississippi on the north side of St. Louis via the Chain of Rocks Bridge. This alignment is now an frontage road of Interstate 270 from the river to Lindbergh Boulevard (U.S. Route 61/U.S. Route 67), then south on Lindbergh to Watson Road. The Chain of Rocks Bridge is a 5,350 feet long bridge spanning the Mississippi River on the north edge of St. Louis Missouri. Its most famous feature is a 22-degree bend occurring at the middle of the crossing, necessary for navigation on the river. The name comes from a "chain" of rocks crossing the Mississippi just below the bridge.
The bridge was privately built as a toll bridge in 1929 at a cost of US$2.5 million and later turned over to the city of Madison, Illinois, the current owner of the bridge. In the late 1930s, Bypass US 66 was designated over this bridge and around the northern and western parts of St. Louis to avoid the downtown city (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.The Chain of Rocks Bridge was added to the Registry of Historic Places on December 1, 2006.
Martin Luther King Bridge
At other times, US 66 also crossed the Mississippi on the Martin Luther King Bridge, and finally on the Poplar Street Bridge.
