61817 -- U.S. ZIP code Municipality (1990): CATLIN, Illinois All ZIPs for this municipality (1990): 61817 Population (2000): 2838 Housing Units (2000): 1107 Land area (2000): 42.236094 sq. miles (109.390977 sq. km) Water area (2000): 0.163520 sq. miles (0.423516 sq. km) Total area (2000): 42.399614 sq. miles (109.814493 sq. km) Located within: Illinois (IL) Location: 40.059068 N, 87.703761 W