Spiral bridge

In the Black Hills of South Dakota, a particular form of spiral bridge, locally called a 'pigtail bridge', was introduced in 1932 by Cecil Clyde Gideon, the self-taught superintendent of Custer State Park turned highway designer.

During the planning for Iron Mountain Road, there was a need to negotiate sudden elevation drops while preserving natural features for this scenic highway; the corkscrew design allowed for a spectacular—albeit expensive—solution to this problem.

In order to blend the bridges with their surroundings, natural materials such as local timber were used.

Turnover bridges were a feature of some early British canals such as the Macclesfield.

They were not universally provided as they were more expensive to build, needing to span both the canal and the towpath.