Glen Rock is a borough in Bergen County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 11,601, reflecting an increase of 55 (+0.5%) from the 11,546 counted in the 2000 Census, which had in turn increased by 663 (+6.1%) from the 10,883 counted in the 1990 Census.
The borough has been one of the state's highest-income communities. Based on data from the American Community Survey for 2013-2017, Glen Rock residents had a median household income of $162,443, ranked 6th in the state among municipalities with more than 10,000 residents, more than double the statewide median of $76,475.
Glen Rock was voted one of the best places to live in New Jersey for its low crime rate, good schools, close proximity to New York City and its high property values, including in 2018, when Niche ranked it the 19th best place to live in New Jersey.
Glen Rock was formed on September 14, 1894, from portions of Ridgewood Township and Saddle River Township during the "Boroughitis" phenomenon then sweeping through Bergen County, in which 26 boroughs were formed in the county in 1894 alone. The main impetus for the break from Ridgewood Township was the decision to have Glen Rock students attend a new school closer to the center of Ridgewood instead of their one-room schoolhouse located at the intersection of Ackerman Avenue and Rock Road. Originally, the borough was to be named "South Ridgewood", but in order to prevent confusion with the neighboring Ridgewood Village, resident Monsieur Viel suggested the alternative name of Glen Rock.
Glen Rock was settled around a large boulder in a small valley (glen), from which it gets its name. The boulder, a glacial erratic weighing in at 570 short tons (520 t) and located where Doremus Avenue meets Rock Road, is believed to have been carried to the site by a glacier that picked up the rock 15,000 years ago near Peekskill, New York and carried it for 20 miles (32 km) to its present location. The Lenape Native Americans called the boulder "Pamachapuka" (meaning "stone from heaven" or "stone from the sky") and used it for signal fires and as a trail marker.
The borough was the site of one of Bergen County's most serious public transportation accidents. In 1911, a trolley operator for the North Jersey Rapid Transit Company, one day away from retirement, died in a crash with an opposing trolley around the intersection of Prospect and Grove Streets that was caused by signal problems. In addition to the death of the opposing trolley operator, 12 people were injured. This crash in part hastened the demise of this transportation mode which ran from Elmwood Park, New Jersey to Suffern, New York and competed with the Erie Railroad.