Los Alamos -- U.S. County in New Mexico Population (2000): 18343 Housing Units (2000): 7937 Land area (2000): 109.345209 sq. miles (283.202780 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 109.345209 sq. miles (283.202780 sq. km) Located within: New Mexico (NM), FIPS 35 Location: 35.871602 N, 106.280313 W Headwords: Los Alamos Los Alamos, NM Los Alamos County Los Alamos County, NM