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Pigtail Bridges


PIERRE, S.D. - In 1939, Cecil Clyde Gideon gained accreditation for designing the first set of pigtail bridges in the world. Gideon was a self-taught man who trained himself in the skill sets which made him a master builder, architect, craftsman, lawman and highway designer.

Gideon’s pigtail bridge design, or “spiral jumpoffs” as he called them, came to life during construction of the scenic Iron Mountain Road. The pigtail bridge design provided a balance between a safe navigable highway, preservation of the pristine Black Hills, and a highway which could traverse the sudden elevation drops of the Hills. In order to maintain the aura of the Black Hills, natural materials such as local timber were used for construction.

The hairpin turns, smooth road and effortless grade change in elevation provided by the pigtail bridges, all the while being surrounded by the beauty of the Black Hills, create one of the most unique and treasured drives in the nation. 

Because of the expense involved with construction, pigtail bridge designs are a rarity, and the best place to experience them is on US Hwy 16A heading south from Mount Rushmore National Memorial. A historical marker acknowledging C.C. Gideon’s accomplishments may be viewed south of Keystone along US Hwy 16A.

The Marks of History series is a project of the South Dakota Office of Tourism designed to highlight historical markers all across South Dakota. Click on the special “Marks of History” link at to access the complete list of articles.

The Marks of History series is part of Goal 1 of the 2010 Initiative to double visitor spending in South Dakota and Goal 4 to enhance history and arts as a tool for economic development and cultural tourism in South Dakota. The Office of Tourism serves under the direction of Richard Benda, Secretary of the Department of Tourism and State Development.


Media Notes: 
The South Dakota Office of Tourism is not responsible for the text included on these markers. Some of the language used at the time of production may not be appropriate by today’s standards. Please view the markers at your own discretion.