Glen Rock (boulder)

About

The Glen Rock is a 570-ton boulder located in Glen Rock, New Jersey, United States. The boulder, which is the namesake of the town in which it is located, is the largest glacial erratic found atop Triassic bedrock in the state of New Jersey. The exact origin of the rock is uncertain, though studies alternatively place its origin in New York State's Hudson Highlands and the New Jersey Highlands. The Glen Rock, which is composed of gneiss, is located in the center of a former glacial lake.

The cultural history of the Glen Rock predates the settlement of New Jersey by European colonists. The Lenape, who referred to the boulder as Pamackapuka, used the rock as a trail marker, a location to build signal fires, and as a throne for chiefs used when presiding over meetings. Later, beginning in colonial times, European settlers to the region used the rock as a landmark on trails and as a marker for land deeds. The Glen Rock, which had been largely submerged under soil, was excavated during road work in 1912; supporting structures were added to the rock during that time to prevent it from collapsing. Following the First World War, a memorial plaque was installed on the rock to honor veterans who had died during the conflict. In 1964, the New Jersey State Office of Historic Sites designated the Glen Rock as a state landmark.