Las Cruces is a city in Doña Ana County, New Mexico, United States. As of the 2000 census, the city had a total population of 74,267. The population was estimated at 91,865 as of July 1, 2008, making it the second largest city in the state. Las Cruces is the center of an agricultural region irrigated by the Rio Grande, which flows just west of the city. The city of Las Cruces bisects the fertile Mesilla Valley, the flood plain of the Rio Grande which extends from Hatch, New Mexico to the west side of El Paso, Texas. Las Cruces is also the home of New Mexico State University. NMSU is New Mexico's only land grant university, citing more than 16,000 graduate and undergraduate students on the main campus. As well as the Organ Mountains that are to the east of the city, the Las Cruces area is also in close proximity to the Dona Ana mountains, the Robledo mountains, and Picacho peak. Las Cruces has a council-manager form of government. It is the county seat of Doña Ana County.