Year constructed: 1924
Alternate name: Iowa River Bridge
Bridge type: Concrete Open Spandrel Arch
National Register of Historic Places status:
Listed
Length: 180 feet
Width: 29.7 feet
Spans: 1
FHWA: 006610
Jurisdiction: City of Iowa Falls
Location: River Street over the Iowa River in Iowa Falls; Section 13, T89N-R21W (Hardin Township)
Details
This long-span concrete arch carries River Street across the Iowa River in the city of Iowa Falls, in north-central Hardin County. Preceded by an earlier structure at this crossing, the existing bridge traces its history to 1921, when plans and specifications for the structure were drafted by Des Moines civil engineer James B. Marsh in behalf of the state highway commission. For this urban crossing, Marsh delineated a single open spandrel arch, with three massive arch ribs carrying a series of concrete columns. The bridge would be handsome in its simplicity, as observed by J.H. Ames, bridge engineer for the Iowa State Highway Commission, to a member of Iowa Falls Community Club: "I am sure that you are going to be pleased with the type of construction that is proposed, as it will make a very artistic and substantial bridge." Moreover, it would be far more stable than the earlier span. "The bridge that crosses the river at that point has been there many years," The Iowa Falls Sentinel reported, "And it is getting in bad condition."
There was some disagreement among the city, the county and the state highway commission regarding the height and location for the proposed structure, but when the county suggested dropping the project altogether, the city reacted strongly. Local citizens actively supported the bridge, citing the important commercial value of the project. Eventually the residents prevailed in securing financial backing for the bridge's construction, and commissioners advertised for competitive bids in late spring of 1922. Awarded the contract that summer, the Weldon Brothers Construction Company of Iowa Falls began work in July by demolishing the earlier bridge. Completed without incident in 1924 for the aggregate sum of $16,900, the Iowa River Bridge continues to carry steady traffic in its urban settings. The structure maintains good physical integrity, with a 1958 widening of its deck and removal of the original guardrails and electroliers as the most serious alteration.
The River Street location has been a pivotal one in Iowa Falls development. Initially a simple ford, the crossing was followed by a timber bridge, then an iron structure, then a 140-foot steel Pratt truss. As the fourth bridge here, the existing concrete arch represents the development of bridge technology in Iowa. Its open spandrel configuration is unusual in Iowa. Relatively few such arches were ever built (all in urban locations like this one), and even fewer remain in use today. Designed by one of the state's foremost bridge engineers, it is an excellent example of its structural type [adapted from Crow-Dolby and Fraser 1992].