61542 -- U.S. ZIP code Municipality (1990): LEWISTOWN, Illinois All ZIPs for this municipality (1990): 61542 Population (2000): 4049 Housing Units (2000): 1815 Land area (2000): 108.178987 sq. miles (280.182278 sq. km) Water area (2000): 0.135673 sq. miles (0.351392 sq. km) Total area (2000): 108.314660 sq. miles (280.533670 sq. km) Located within: Illinois (IL) Location: 40.393090 N, 90.137480 W