From the record
“Hawkeye Creek Bridge is a historic structure located in a rural area northeast of Mediapolis, Iowa, United States. The Des Moines County Board of Supervisors contracted with Clinton Bridge and Iron Works on September 23, 1909, to design and build this bridge.”
Wikipedia article Hawkeye Creek Bridge, CC BY-SA 4.0.
One of 35 National Register listings published here for Des Moines County · listed in 1998 · category: Structure · built in 1909.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service