Albuquerque is the largest city in the state of New Mexico, United States. It is the county seat of Bernalillo County and is situated in the central part of the state, straddling the Rio Grande. Albuquerque is the 57th-largest United States metropolitan area. The Albuquerque MSA population includes the city of Rio Rancho. Roughly half the people in New Mexico live in the Albuquerque area.