62850 -- U.S. ZIP code Municipality (1990): JOHNSONVILLE, Illinois All ZIPs for this municipality (1990): 62850 Population (2000): 579 Housing Units (2000): 238 Land area (2000): 40.057835 sq. miles (103.749311 sq. km) Water area (2000): 0.417693 sq. miles (1.081819 sq. km) Total area (2000): 40.475528 sq. miles (104.831130 sq. km) Located within: Illinois (IL) Location: 38.513119 N, 88.589112 W