Dallas -- U.S. County in Iowa Population (2000): 40750 Housing Units (2000): 16529 Land area (2000): 586.465000 sq. miles (1518.937313 sq. km) Water area (2000): 5.264133 sq. miles (13.634041 sq. km) Total area (2000): 591.729133 sq. miles (1532.571354 sq. km) Located within: Iowa (IA), FIPS 19 Location: 41.682923 N, 94.021682 W Headwords: Dallas Dallas, IA Dallas County Dallas County, IA