This bridge was built as part of the Oahe Dam project. It provides easy
access to the dam power house from Fort Pierre without traffic having to
go up and over the dam. This is convenient for both the work crew and
folks using the recreation areas below the dam. The bridge is located
about 2/3 of a mile down stream of the overflow outlets on the west end
of the dam. The river channel carries the overflow water to the main
channel of the Missouri River.
The Powerplant Road Bridge is a relatively simple structure. It was built
by driving tubular piles into the riverbed. Some piles are vertical to
better carry the load of the bridge, while some are set at an angle to
help keep the bridge from moving sideways. There are 14 piles for each
pier. A concrete cap was placed on top of the piles. The bridge steel
was then erected across the piles. Finally, the road deck was built on
top of the steel girders.