South Salem Covered Bridge spans Buckskin Creek on Lower Twin Road in Buckskin Township, northwestern Ross County, Ohio. Built in 1873 as a wooden Smith truss using a design patented by Ohio engineer Robert Smith in the late 1860s, it is eight wooden panels wide, rests on stone abutments, and is sheltered by a metal roof. These features have helped preserve an important example of historic bridge engineering. Its significance was formally recognized in 1975 when it was listed on the National Register of Historic Places, and its rarity is especially notable because it is the only covered bridge surviving in Ross County.