The Swiftwater Covered Bridge is a historic covered bridge that carries Porter Road over the Wild Ammonoosuc River in Bath, New Hampshire. Built in 1849, it is one of New Hampshire's few surviving 19th-century covered bridges and a well-preserved example of the Paddleford truss design. 

It is a locally distinctive single-span Paddleford truss design, with laminated arches and steel beam reinforcements added in the 20th century. The bridge has an overall length of 173 feet 8 inches and two clear spans of 77 feet 6 inches and 57 feet 6 inches. The roadbed is 14 feet 6 inches wide, with a vertical clearance of 12 feet 9 inches. It rests on lightly mortared split granite abutments topped with concrete footings. The roof is made of corrugated metal, and the sides are sheathed in vertical planking to a height of eight feet, leaving an exposed area above. Its portals are also covered in vertical planking, but do not extend all the way to the ground.

The bridge, the fourth on the site, was built in 1849; the first two bridges, dating back to 1810, were washed away by floods. It was probably built under the auspices of Joseph Fifield and John Carbee, town officials responsible for its highways and bridges. Its design, an unpatented truss by New Hampshire native Peter Paddleford, may have been used due to local connections with Paddleford associates. The bridge is said to have survived the use of explosives to clear logjams in the area.

The bridge was carried away in 1818 by a flood and replaced in the same year. Again, the bridge was destroyed by a flood in 1828. The third bridge was erected in 1829 and remained at the site until 1849. At that time, it was dismantled and replaced by the current bridge. The state rebuilt the bridge in 1977 for $34,347. The rebuilding costs were shared by the state and the town. This section of the river was used to float logs to the sawmill. Often, log jams presented a hazard to the bridge. In one case, dynamite was used to break up a log jam, and although the blast was successful, logs had to be removed from the roof of the bridge.

Of the 400 covered bridges that once stood in the state of New Hampshire, as of 2019, only 54 remain.

The Swiftwater Bridge was added to the National Register of Historic Places in 1976.

Located at:  N44 08.036   W71 57.049        -       WGCB #29-05-02

Photographed in July of 2019

Photos by Millard Farmer