[2] Completed in 1921, this concrete cantilevered deck girder bridge replaced an earlier timber pile structure.

It was designed by the Iowa State Highway Commission the previous year, and the Polk County Board of Supervisors awarded the construction contract to Ben Cole of Ames.

It is considered one of the most technologically significant of Iowa's concrete girder bridges.

[1] While it remains in place, the Herrold Bridge was replaced by a newer span slightly downstream.

This article about a property in Polk County, Iowa on the National Register of Historic Places is a stub.