Natural Pier Bridge is a steel Warren through truss bridge spanning the Clark Fork river located 1 mile (1.6 km) west of Alberton, Montana, United States, which incorporates a natural rock outcrop as anchorage for a pier. It was nominated to the National Register of Historic Places as part of a related group of historic Montana bridges known as Montana's Historic Steel Truss Bridges and achieved listing on January 4, 2010.