River Vale is a township in Bergen County, New Jersey, United States. As of the 2010 United States Census, the township's population was 9,659, reflecting an increase of 210 (+2.2%) from the 9,449 counted in the 2000 Census, which had in turn increased by 39 (+0.4%) from the 9,410 counted in the 1990 Census. The township was ranked #29 on the 100 Best Places to Live 2007 survey published by CNN/Money magazine.
River Vale was formed as a township on April 30, 1906, from portions of both Hillsdale Township (now Hillsdale Borough) and Washington Township. The township was named for its location along the Hackensack River.
On January 5, 1904, the temperature in River Vale fell to , the lowest temperature ever recorded in New Jersey.
Before 1841, the area comprising River Vale was part of Harrington Township. It used to be known as the "Over Kill Neighborhood" or just "Over Kill" — it being over the kill (Hackensack River) from Tappan. Its southern part, known as Eastwood (named in contrast to Westwood), became an independent borough in 1894, but was dissolved and re-absorbed into Washington Township in 1896.
River Vale was incorporated as a township in 1906, formed from portions of both Hillsdale and Washington Township. On July 15, 1929, part of River Vale was ceded to Park Ridge. On May 20, 1959, territory was acquired from Montvale.
In 1967, a mass grave site was discovered in River Vale from an event in 1778 during the American Revolutionary War, the Baylor Massacre. This became widely known due to a February 1968 report to the Bergen County Board of Chosen Freeholders, "1778 - The Massacre of Baylor's Dragoons." The burial site was made into a county park that was dedicated on October 15, 1972.
On July 28, 1994, the residents of River Vale voted to recall Mayor Walter Jones, Councilwoman Patricia Geier and Councilman Bernard Salmon, following a battle between residents and the mayor and some council members over the mayor's plan to merge River Vale's 9-1-1 center to a regional dispatch location in Park Ridge.
A River Vale resident, Henry Hoffman, directed the scrapping of the in Kearny from 1958 to 1960. Following Hoffman's death in 1965, the stern plate of the Enterprise was placed on a Little League baseball field as a memorial. The field was later named Hoffman Field. On October 2, 2000, the stern plate was moved to the township's Veterans' Memorial Park.
In March 2004, the township became the first municipality in the state to be placed on probation by the Municipal Excess Liability Joint Insurance Fund, a fund that covers legal expenses of member municipalities and government agencies. The issue was due to the number and scope of legal cases against the township, its employees and its governance, plus what David Grub, chief executive of the fund, called "a general environment of personal attack". The fund urged the township to update employment practices and better train managers to avoid liabilities. As a result of these issues, The New York Times called the township "small but litigious".