61084 -- U.S. ZIP code Municipality (1990): STILLMAN VALLEY, Illinois All ZIPs for this municipality (1990): 61084 Population (2000): 2796 Housing Units (2000): 1049 Land area (2000): 34.718957 sq. miles (89.921683 sq. km) Water area (2000): 0.029225 sq. miles (0.075692 sq. km) Total area (2000): 34.748182 sq. miles (89.997375 sq. km) Located within: Illinois (IL) Location: 42.112207 N, 89.186330 W