61604 -- U.S. ZIP code Municipality (1990): PEORIA, Illinois All ZIPs for this municipality (1990): 61602 61604 61605 61606 61615 Population (2000): 33587 Housing Units (2000): 14477 Land area (2000): 17.855502 sq. miles (46.245536 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 17.855502 sq. miles (46.245536 sq. km) Located within: Illinois (IL) Location: 40.709237 N, 89.636333 W