Hudson County, New Jersey Hudson County, New Jersey Hudson County, a county in the U.S. state of New Jersey, lies west of the lower Hudson River, which was named for Henry Hudson, the sea captain who explored the area in 1609. Part of New Jersey's Gateway Region in the New York metropolitan area, Jersey City is its largest city and county seat. As of the 2017 Census estimate, Hudson County was the fastest-growing county in New Jersey compared to 2010; the county's population was 691,643, making it the state's 4th-most populous county, an increase of 9.0% from the 2010 United States Census, when its
River Vale, New Jersey section bordering Emerson to the south, Harrington Park to the southeast, Old Tappan to the east, and Pearl River, New York to the north. Its borders are defined by the Hackensack River to the east, which was dammed to form Lake Tappan, and Pascack Brook to the south. The northern border is defined by the New York-New Jersey state border. The western border has several sections, including a section defined by an unnamed creek and a section defined by Cedar Lane. The southern portion of the township lies between the Hackensack River and Pascack Brook, and is relatively flat. The