Mount Orne Covered Bridge spans the Connecticut River between South Lancaster, New Hampshire, and Lunenburg, Vermont, carrying Elm Street to River Road through a rural valley crossing. Built in 1911 by the Berlin Construction Company after flooding destroyed an earlier bridge in 1905, it has long served as a shared interstate link maintained by the two towns. The bridge has two wood-and-iron Howe truss spans on stone abutments and piers, and it is one of only two Howe truss bridges across the Connecticut River. Listed on the National Register of Historic Places in 1976, it was repaired and rededicated in 1983 and closed again in 2023 after vehicle damage.