May 16, 2017: A marker for Shellsburg depicts the bridge right behind it, at the south end of the business district.
The Nov. 1 Benton County Supervisors meeting had some updates from the county engineer that affect noteworthy locations. The Star Press Union (via Jim Magdefrau, who also writes on his personal website) has a recap.
The video of the meeting (timestamp: 19:45) shows the engineer explaining that the city of Shellsburg has secured funding for a new bridge just south of downtown. The historic arch bridge will be restricted to pedestrians and bicycles. The road makes a sharp turn to cross this bridge, so the new one likely will be designed to cross Bear Creek south of it and align to the railroad crossing to the south.
The Iowa DOT has a page about this 1915 bridge because of its significance in early Iowa State Highway Commission history, although this bridge was never part of the state system. The bridge features “a more studied architectural expression with bichrome concrete detailing, molded concrete balustrades and incised spandrel panels” due to its location in a town rather than a rural setting, the webpage says. If you see concrete elements like this on other old bridges, although not as elaborate, you can be sure it’s either a 1910s bridge or designed to mimic one.