Caldwell, ID -- U.S. city in Idaho Population (2000): 25967 Housing Units (2000): 9603 Land area (2000): 11.342997 sq. miles (29.378226 sq. km) Water area (2000): 0.013067 sq. miles (0.033843 sq. km) Total area (2000): 11.356064 sq. miles (29.412069 sq. km) FIPS code: 12250 Located within: Idaho (ID), FIPS 16 Location: 43.658239 N, 116.680390 W ZIP Codes (1990): 83605 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Caldwell, ID Caldwell