Rio Arriba -- U.S. County in New Mexico Population (2000): 41190 Housing Units (2000): 18016 Land area (2000): 5857.631640 sq. miles (15171.195655 sq. km) Water area (2000): 38.471738 sq. miles (99.641340 sq. km) Total area (2000): 5896.103378 sq. miles (15270.836995 sq. km) Located within: New Mexico (NM), FIPS 35 Location: 36.448433 N, 106.718230 W Headwords: Rio Arriba Rio Arriba, NM Rio Arriba County Rio Arriba County, NM