Lansing Bridge, Mississippi River Bridge
Rigid-Connected Cantilever Through Truss
National Register of Historic Places status:
1,127’ Five segments (two – 237’ anchor segments, two – 178’ cantilever segments, one – 297’ suspended center span)
Iowa DOT / Wisconsin DOT
Iowa 9/Wisconsin 82 [T99N-R3W Section 29]
"A reality! Finished!" The Book of the Black Hawk bridge, enthused at the structure's dedication in 1931. "The Black Hawk Bridge, three quarters of a million dollars of steel and concrete, linking the states of Iowa and Wisconsin, running eastward from Lansing across the Winneshiek Bottoms to De Soto, is a reality. It is the first passenger bridge to join these two states, the result of more than a generation of dreaming and scheming, planning and promoting--and two years of actual construction." Planning for the bridge had begun in 1898 by Lansing businessmen J.P. Conway and Tom Bakeman. The two promoted the proposed structure for years as a boon to the community, eventually forming the Interstate Bridge Company in 1914 to secure a Congressional charter for the bridge. The charter, secured in 1916, was turned over to the Iowa-Wisconsin Bridge Company in late 1929. Under the direction of Des Moines financier John Thompson, the latter firm sold bridge bonds to finance construction, hired Minneapolis engineer Melvin B. Stone to design the bridge, and contracted with the McClintic-Marshall Company of Chicago to fabricate and erect the trusses. The bridge was christened the Black Hawk Bridge to honor famous Indian Chief Black Hawk.
The bridge was dedicated on June 17, 1929, with the governors of Iowa, Wisconsin and Minnesota present. Thebridge functioned as a toll structure until flooding washed out some of the approach spans over the Wisconsin bottoms in 1945. It stood unused for several years until the approaches were re-constructed and the bridge re-dedicated in May 1957. The Black Hawk Bridge now carries traffic as a free bridge, in essentially unaltered condition.
The importance of the Black Hawk Bridge to commerce and transportation in northeastern Iowa can hardly be understated. The only highway bridge over the Mississippi River in the region at the time of its completion, the Black Hawk Bridge is historically significant for its role in the development of northeast Iowa. Although its design and dimensions fit within the mainstream of bridge technology of the time, the structure is technologically significant as an uncommon, large-scale example of cantilevered truss design. Few such cantilevered trusses were erected in Iowa, those primarily over the Mississippi or Missouri Rivers, and even fewer remain in use today. The Black Hawk Bridge is one of only five such long-span, cantilevered trusses in Iowa.
[adapted from Fraser and McWilliams 1992]
Bridges of the McClintic-Marshall Bridge