61254 -- U.S. ZIP code Municipality (1990): GENESEO, Illinois All ZIPs for this municipality (1990): 61254 Population (2000): 11399 Housing Units (2000): 4557 Land area (2000): 160.746000 sq. miles (416.330212 sq. km) Water area (2000): 0.256164 sq. miles (0.663461 sq. km) Total area (2000): 161.002164 sq. miles (416.993673 sq. km) Located within: Illinois (IL) Location: 41.464473 N, 90.158548 W