61740 -- U.S. ZIP code Municipality (1990): FLANAGAN, Illinois All ZIPs for this municipality (1990): 61740 Population (2000): 1746 Housing Units (2000): 696 Land area (2000): 72.756051 sq. miles (188.437300 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 72.756051 sq. miles (188.437300 sq. km) Located within: Illinois (IL) Location: 40.882858 N, 88.857390 W