61814 -- U.S. ZIP code Municipality (1990): BISMARCK, Illinois All ZIPs for this municipality (1990): 61814 Population (2000): 1249 Housing Units (2000): 497 Land area (2000): 25.223056 sq. miles (65.327413 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 25.223056 sq. miles (65.327413 sq. km) Located within: Illinois (IL) Location: 40.231345 N, 87.581630 W