61241 -- U.S. ZIP code Municipality (1990): GREEN ROCK, Illinois All ZIPs for this municipality (1990): 61241 Population (2000): 6944 Housing Units (2000): 2730 Land area (2000): 19.083258 sq. miles (49.425410 sq. km) Water area (2000): 0.061189 sq. miles (0.158478 sq. km) Total area (2000): 19.144447 sq. miles (49.583888 sq. km) Located within: Illinois (IL) Location: 41.483484 N, 90.340469 W