Hillsborough, NJ 08844
The Rock Brook Bridge is a random-rubble stone bridge with two arches and an open span. The bridge is located at the junction of Long Hill and Dutchtown-Zion Roads. H. Hageman, who was almost certainly a local mason, built it in 1825. The open span replaced a third arch, which was washed out by a storm in 1891. The structure is 41 feet long and 16 feet wide. The earliest part of the bridge is a good example of local bridgebuilding methods in the county during the early 19th century, as well as stone construction in general. The bridge is maintained by Somerset County.