The Chamberlain is the only surviving bridge of the original five. The others were replaced as the river rose due to flood control dams put in place over time.
For its first 30 years of statehood, South Dakota was effectively two states. The Missouri river cut across the land forming a barrier to economical development in the west. Conventional wisdom at the time estimated the cost of permanent bridges across the Missouri at $1 million apiece. But budding engineer John Edward Kirkham, through the strict application of a classic principle of bridge design, built five steel and concrete truss bridges for $2 million total.
Kirkham knew that bridges can be built least expensively when the cost of the foundations equals the cost of the superstructure minus the floor system. For example, if longer piers were required due to soil conditions, he would lengthen trusses to reduce the cost of the superstructure and offset the increased cost of the foundation.
The Chamberlain, Wheeler, Mobridge, Pierre and Forest City bridges were simple, elegant structures that played a big role in South Dakota's early growth.
Facts