The bridge over the Great Miami River in Logansville, Ohio, carrying County Road 21, originally called the Logansville and Muchinippi Free turnpike, was constructed in 1882 by the Massillion Bridge Company of Massillion, Ohio. It was found eligible for the National Registry of Historic Places as a surviving example of a Whipple through truss design built by a significant Ohio bridge company. Squire Whipple developed this bridge type in 1847 and, as the first engineer to understand stresses in truss members, created a formula for calculating actual stress in bridge trusses, allowing more scientific bridge design. Using these methods, he designed longer spans with diagonals crossing two panels, a defining feature of Whipple truss bridges. Also known as double-intersection Pratt trusses, Whipple trusses were among the most successful long-span bridge designs of the mid to late 1800s, reaching lengths of up to 300 feet and serving both railroad and vehicular traffic. This bridge is 143 feet long. It carried one lane of traffic until it was bypassed and preserved in 2020 by Logan County Engineer Scott Coleman, P.E., P.S. The Massillion Iron Bridge Company was founded in 1869 and incorporated in 1873 by Joseph Davenport, offered a catalog of dozens of steel trusses, and installed bridges throughout the Midwest before closing in the early 1900s. Numerous Massillion Bridge Company structures still stand across Ohio, with several listed in the National Registry of Historic Places and the Ohio Historic Inventory. Only eleven Whipple through trusses survive in Ohio. To meet modern traffic demands and vehicle size, a new 155 feet single-span plate girder bridge was built north of the historic truss, with Eagle Bridge Company as contractor, DLZ Ohio, Inc. providing construction inspection services, and federal funds paying 80 percent of the estimated $1,838,032 project cost.