Irwin, ID -- U.S. city in Idaho Population (2000): 157 Housing Units (2000): 125 Land area (2000): 2.126275 sq. miles (5.507028 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 2.126275 sq. miles (5.507028 sq. km) FIPS code: 40510 Located within: Idaho (ID), FIPS 16 Location: 43.388220 N, 111.268118 W ZIP Codes (1990): Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Irwin, ID Irwin