Adairs Covered Bridge, also known as the Cisna Mill Covered Bridge, is a historic wooden bridge in Southwest Madison Township near Blain, Pennsylvania, carrying a road over Shermans Creek. Built in 1864 as a Burr Truss span, it reflects a widely used 19th-century American design that joined an arch and truss for strength. At 150 feet long, it stands as a substantial example of rural bridge building. Rebuilt in 1919, it remains significant both for its survival and for its connection to Pennsylvania’s covered-bridge tradition and rural transportation history. Its historical importance was formally recognized with its listing on the National Register of Historic Places in 1980.