Corbett's Mill Bridge, Spanning Maquoketa River at abandoned county road, 3 miles northeast of Scotch Grove, Scotch Grove, Jones County, IA

Significance: The Corbett's Mill bridge is an example of what was once a common bridge form: the bowstring arch-truss. In the 1860s and 1870s bowstring arch-trusses were used extensively because of their great structural efficiency and relatively low construction costs. During this period many thousands of bowstring arch-trusses were built in the nation. Because the development of Iowa's transportation system coincided with this period, the number of bowstrings built in the state numbered in the many hundreds. Most of these were built by the large Ohio bridge companies, such as the King Iron Bridge and Manufacturing Company, the Massillon Bridge Company, and the Wrought Iron Bridge Company. The Corbett's Mill bridge is an excellent example of a bowstring arch-truss that was built by a smaller company: the Buckeye Bridge Company, also of Ohio.
Unprocessed Field note material exists for this structure: N232
Survey number: HAER IA-60
Building/structure dates: 1871 Initial Construction
National Register of Historic Places NRIS Number: 85000722