The US 20 bridge over the Iowa River is a major transportation improvement and a distinctive feat of modern engineering.

Constructed near the town of Steamboat Rock in Hardin County , Iowa , the bridge is the first launched steel I-girder highway bridge in the United States and one of the longest I-girder spans ever launched in the world.

The unique construction method was used to preserve the Iowa River Greenbelt, one of the few remaining old-growth woodlands in north central Iowa . The bridge design and the construction process were developed following years of intensive study into the area's biology and cultural resources, and with the goal of preserving this environmental treasure.

The opening of the bridge in August 2003 was also a major step towards the decades-old dream of a four-lane US 20 across Iowa . US 20 is now a four-lane highway from the Mississippi River to Fort Dodge .

Our web site documents the three-year construction process with a Construction Photo Album containing more than 200 photos; with multimedia , including computer animation and a time-lapse video clip of the bridge launch; and a Technical Library , with technical diagrams and other information.


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