61054 -- U.S. ZIP code Municipality (1990): MOUNT MORRIS, Illinois All ZIPs for this municipality (1990): 61054 Population (2000): 3991 Housing Units (2000): 1762 Land area (2000): 35.957742 sq. miles (93.130121 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 35.957742 sq. miles (93.130121 sq. km) Located within: Illinois (IL) Location: 42.046139 N, 89.440253 W