High Bridge is a borough in Hunterdon County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 3,648, reflecting a decline of 128 (-3.4%) from the 3,776 counted in the 2000 Census, which had in turn declined by 110 (-2.8%) from the 3,886 counted in the 1990 Census.
High Bridge was originally incorporated as a township by an act of the New Jersey Legislature on March 29, 1871, from portions of Clinton Township and Lebanon Township. On February 19, 1898, the borough of High Bridge was incorporated from portions of the township, with the remainder returned to Clinton and Lebanon Townships five days later.
The borough is located on the South Branch of the Raritan River in the north central part of Hunterdon County. Water from the South Branch was a valuable power source for one of the first ironworks in the United States, established in the 1740s by William Allen and Joseph Turner of Philadelphia. Allen was the mayor of Philadelphia, a Chief Justice of Pennsylvania, and a prominent landowner in New Jersey. In 1859, the Central Railroad of New Jersey began a five-year construction project of a 112-foot-high (34 m), 1,300-foot-long (400 m) bridge across the river from which structure the locality ultimately took its name.
According to the United States Census Bureau, the borough had a total area of 2.431 square miles (6.297 km2), including 2.389 square miles (6.188 km2) of land and 0.042 square miles (0.109 km2) of water (1.74%). It is drained by the South Branch of the Raritan River.
High Bridge borders the Hunterdon County municipalities of Clinton Township and Lebanon Township.
Unincorporated communities, localities and place names located partially or completely within the township include Jericho Hill, Pierce Heights and Silverthorn.
The 2010 United States Census counted 3,648 people, 1,418 households, and 1,003.944 families in the borough. The population density was 1,526.9 per square mile (589.5/km2). There were 1,481 housing units at an average density of 619.9 per square mile (239.3/km2).