 The township is bordered by Montvale to the northwest, Park Ridge, Woodcliff Lake (a very small section) and Hillsdale to the west, Westwood to the southwest, a small 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.