 Prior to the creation of ZIP Codes as a way to uniquely identify addresses, United States Postal Service policy was that two post offices in a state could not have the same name, and there was already a "Woodcliff" in Hudson County.On January 1, 1956, and again on July 1, 1958, Woodcliff Lake exchanged sections of land with Park Ridge.On October 13, 1960, portions were exchanged with Hillsdale.