Monsrud Bridge

This small-scale bowstring arch-truss spans Paint Creek northwest of Waterville in Paint Creek Township. Allamakee County records indicate that the bridge was erected in 1887 by the King Iron Bridge and Manufacturing Company, based on an 1887 bridge patent. The iron structure features typical King detailing, with its square tubular arch ribs, star iron verticals and threaded rod diagonals, and lateral bracing. The bridge once carried a county road, but has since been replaced with a low water crossing and abandoned in place. Other than this, the Monsrud Bridge remains in unaltered condition.

The bowstring arch-truss was the iron span of choice for Iowa counties in the late 1860s and 1870s. Marketed extensively throughout the Midwest by such industry giants as the King Iron Bridge and Manufacturing Company and the Wrought Iron Bridge Company, these often patented bridge forms featured a wide range of span lengths, economical fabrication cost, and relatively quick erection. The proliferation of the bowstring corresponded with the initial development of Iowa's road system; as a result, perhaps thousands of these prototypical iron spans were erected throughout the state. The bowstring had some rather severe structural flaws, however, relating primarily to the lateral stability of the arches, and it was largely superseded by the pin-connected truss in the early 1880s. Despite this, some bowstrings were still erected in Iowa in the 1880s, although the number dwindled precipitously by the decade's end. Through subsequent attrition, almost all of Iowa's bowstrings have since been replaced and demolished. Now less than twenty remain in place. Although it no longer carries traffic, the Monsrud Bridge is historically and technologically significant as one of the last remaining examples in the state of what was once a mainstay structural type.