Firth, ID -- U.S. city in Idaho Population (2000): 408 Housing Units (2000): 148 Land area (2000): 0.190681 sq. miles (0.493861 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 0.190681 sq. miles (0.493861 sq. km) FIPS code: 27910 Located within: Idaho (ID), FIPS 16 Location: 43.305519 N, 112.183938 W ZIP Codes (1990): 83236 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Firth, ID Firth