The Dover Bridge was first built in 1811 at a ferry crossing, and the failure of its wooden structure along with storm damage during the 19th century led to replacements in 1860 and 1898. After the State Roads Commission was formed by 1908, wooden bridges were replaced with iron to support vehicle traffic, and the commission oversaw construction of a 1912 bridge and its steel replacement in 1933 as agricultural products and seafood were increasingly shipped by road rather than waterways. The 650-foot-long bridge built in 1933 is rare in design because its three spans combine features of a movable swing bridge and a metal Warren truss bridge. Swing bridges and metal truss bridges were favored for reliability and affordability despite the slow-moving central pivot swing mechanism. Its control house stands on the northwest approach rather than at the more common midpoint and contains the machinery that moves the bridge. The 1933 Dover Bridge is eligible for listing in the National Register of Historic Places for its historic and engineering significance, and it is being preserved for public education and enjoyment. A new Dover Bridge is the sixth bridge at this location and the first stationary structure.