Waterloo Covered Bridge carries Newmarket Road over the Warner River near Waterloo Falls in western Warner, New Hampshire, and remains a working one-lane bridge. Built in 1859–60 to replace an earlier span, it is one of New Hampshire’s few surviving 19th-century covered bridges. The single-span Town lattice truss served a crossing that was once important to a small cluster of water-powered industries at Waterloo Falls, now gone except for foundation remains. Rehabilitated with concrete foundations in 1970, the bridge is significant both as a rare surviving covered bridge and as part of the area’s industrial and transportation history.