12136 -- U.S. ZIP code Municipality (1990): OLD CHATHAM, New York All ZIPs for this municipality (1990): 12136 Population (2000): 875 Housing Units (2000): 486 Land area (2000): 19.049010 sq. miles (49.336707 sq. km) Water area (2000): 0.015556 sq. miles (0.040290 sq. km) Total area (2000): 19.064566 sq. miles (49.376997 sq. km) Located within: New York (NY) Location: 42.437594 N, 73.555997 W