The Mt. Olive Road Covered Bridge in northwestern Vinton County, Ohio, northeast of Allensville, stands along a valley route that was once a major early transportation corridor in southern Ohio. Until about 1825, travelers used Mt. Olive Road heavily between Marietta and Chillicothe during the first decades of white settlement in the region. Built on stone piers with a metal roof and a simple queen post truss, the bridge was designed by local engineer George Washington Pilcher, a leading southeastern Ohio bridge builder. Also known as the Grandstaff Bridge, it was listed on the National Register of Historic Places in 1973 for both its preserved engineering and transportation significance.