Mackinac Bridge is somewhat famous, built in the 1950s.
They more or less do continuous maintenance during the warmer months of the year.
(So older than 50, but younger than 100)
They more or less do continuous maintenance during the warmer months of the year.
(So older than 50, but younger than 100)
https://en.wikipedia.org/wiki/Zilwaukee_Bridge
Sticking with the mid-western therme, the Chicago Skyway was built in 1958