"The Lower Plymouth Rock Bridge is one of the few intact examples remaining of what had once been the standard rural roadway bridge type of the 1870s in America: the bowstring arch-truss. This patented tubular arch design was marketed extensively throughout the United States and Canada by the Wrought Iron Bridge Company of Canton, Ohio, one of this country's most important 19th century iron bridge fabricators. The Lower Plymouth Rock Bridge is the oldest bowstring remaining in its original position in Winneshiek County.
Clayton B. Fraser, January 1986 `
Dimensions
Length of largest span: 128.0 ft.
Total length: 130.0 ft.
Deck width: 18.0 ft.
Approximate latitude, longitude
+43.43171, -91.99725(decimal degrees) 43°25'54" N, 91°59'50" W (degrees°minutes'seconds")