61021 -- U.S. ZIP code Municipality (1990): DIXON, Illinois All ZIPs for this municipality (1990): 61021 Population (2000): 23360 Housing Units (2000): 9338 Land area (2000): 153.922324 sq. miles (398.656971 sq. km) Water area (2000): 0.275049 sq. miles (0.712373 sq. km) Total area (2000): 154.197373 sq. miles (399.369344 sq. km) Located within: Illinois (IL) Location: 41.843702 N, 89.476362 W