Albuquerque is the largest city in the U.S. state of New Mexico. It is the county seat of Bernalillo County, and it is situated in the central part of the state, straddling the Rio Grande. The city population was 552,804 as of the 2011 population estimates from the United States Census Bureau and ranks as the 32nd-largest city in the U.S. It has a 2012 estimated metropolitan population of 901,700 according to the US Census. Albuquerque is the 53rd-largest United States metropolitan area. The Albuquerque MSA population includes the city of Rio Rancho, and forms part of the larger Albuquerque – Santa Fe – Las Vegas combined statistical area, with a total population of 1,146,049 as of the 2010 Census.