Lyon -- U.S. County in Kansas Population (2000): 35935 Housing Units (2000): 14757 Land area (2000): 850.869088 sq. miles (2203.740728 sq. km) Water area (2000): 4.266976 sq. miles (11.051416 sq. km) Total area (2000): 855.136064 sq. miles (2214.792144 sq. km) Located within: Kansas (KS), FIPS 20 Location: 38.428144 N, 96.148192 W Headwords: Lyon Lyon, KS Lyon County Lyon County, KS