Missouri's original Centennial road system included secondary spurs with letter suffixes. Only two such roads remain in Missouri. Both of them are off Missouri 64 in west-central Missouri.
At the left is a reassurance marker for Missouri 64A as it loops into Bennett Springs State Park (shown here at its eastern entrance). The sign assembly on the right shows the markers at the nearby intersection with Missouri 64. (You can see a reassurance marker for Missouri 64 in the background, too.)
The other highway with a letter suffix, Missouri 64B, is a spur into Pomme De Terre State Park, some 35 miles to the west of 64A.
These photographs were taken in 2002.