Walden is the largest of three villages of the town of Montgomery in Orange County, New York, United States. The population was 6,818 at the 2020 census. It has the ZIP Code 12586 and the 778 telephone exchange within the 845 area code. Walden is part of the Kiryas Joel−Poughkeepsie−Newburgh, NY Metropolitan Statistical Area as …Walden is the largest of three villages of the town of Montgomery in Orange County, New York, United States. The population was 6,818 at the 2020 census. It has the ZIP Code 12586 and the 778 telephone exchange within the 845 area code. Walden is part of the Kiryas Joel−Poughkeepsie−Newburgh, NY Metropolitan Statistical Area as well as the larger New York−Newark−Bridgeport, NY-NJ-CT-PA Combined Statistical Area.