13820 -- U.S. ZIP code Municipality (1990): ONEONTA, New York All ZIPs for this municipality (1990): 13820 Population (2000): 21058 Housing Units (2000): 8238 Land area (2000): 107.079805 sq. miles (277.335410 sq. km) Water area (2000): 0.280097 sq. miles (0.725449 sq. km) Total area (2000): 107.359902 sq. miles (278.060859 sq. km) Located within: New York (NY) Location: 42.469761 N, 75.051929 W