Kidd's Mill Covered Bridge

By Doug - January 26, 2022

Built in 1868 to replace a span destroyed by flooding along the Shenango River, the Kidd's Mills Covered Bridge is the last remaining historic covered bridge located in Mercer County, Pennsylvania. Known in Mercer County's inventory as Bridge # 1801, the bridge is located on Township Road 471, about a half mile east of PA 18, near the community of Transfer in Pymatuning Township. The 124 foot long covered bridge was designed using a Smith through truss design and is the easternmost covered bridge that utilizes the Smith through truss design. The bridge was built by the Smith Bridge Company of Tipp City, Ohio (formerly known as Tippecanoe City).

The Smith truss design for a covered bridge was kind of like the bridge version of a Craftsman home, as it was not constructed on site. Devised and patented in 1867 by Robert Smith, both the tension and compression members were all wood. During the period of 1867 to 1870, Smith built fifteen of these patented structures in Miami County, Ohio. Smith usually assembled the trusses in his home yard and shipped them by rail to the destination. Standard charges for a complete bridge put up by the Smith Bridge Company was $18 per foot for a bridge span of 125 feet.

The Smith truss was designed specifically to compete with iron by using timber as efficiently as possible, and for a decade, the Smith Bridge Company was rather successful at this practice. Historians estimate that several hundred Smith trusses were built in nine states, being most popular in Ohio, Indiana, California and Oregon, with the Kidd's Mill Covered Bridge being the only remaining bridge of Smith's design that is still standing east of Ohio. The cost-effectiveness of iron led to the abandonment of the Smith truss design in the 1880s, but Smith's company made the transition and continued to build bridges until 1891.

The Kidd's Mill Covered Bridge carried traffic for well over a century. In 1963s, the covered bridge was bypassed and slated for demolition, but Mercer County adopted a resolution to maintain the structure as an historic landmark. The bridge continued to carry local traffic until 1979, when an overloaded vehicle fractured several truss members and rendered the bridge unsafe. In 1989, Mercer County leased the bridge for 99 years to the Shenango Conservancy, who restored the bridge in 1990 and maintains the bridge as an historic landmark with a local park, which you can visit today.