McDermott Bridge #18
North of Route 123A
Three bridges previously stood on the site of the McDermott Bridge, which is also known as the Cold River Bridge. They were built in 1790, 1814 and 1840 and were all of the pole and plank type. Sandford Granger owned a sawmill on Fall Mountain Brook from 1838 until 1851. Virgin timber removed from the mountain was used in the construction of his bridges. The current structure was built by his son Albert S. Granger. The current bridge is braced by cables and is only open to foot traffic.
Year of Construction: - 1869
Original Cost: - $450
North of N.H. Route 123A, two miles north of Alstead Village in Langdon.
Town lattice truss with light arches. The bridge is 81'0" long with a clear span of 76'0". It has an overall width of 16'6" with a roadway width of 12'1" and a maximum vertical clearance of 11'1". It is braced by cables attached to the new highway bridge which bypassed it in 1964. It is now used for foot traffic only.