Stone side of the viaduct. The concrete addition can be seen on the far side of the arches.
When built in 1851, it carried a double track of the original Baltimore and Ohio Railroad main line. In 1916 the viaduct was widened to accommodate two more tracks. The addition is a Melan-type reinforced concrete bridge of identical configuration built against the south face of the original stone bridge.[2] As the state boundary follows the southern bank of the Potomac, nearly all of the bridge is located in Garrett County, Maryland.
