State in southwestern USA, bordered in the north by Colorado , to the east by Oklahoma , to the east and south by Texas , to the south by Mexico, and to the west by Arizona ; its northwest corner borders Arizona, Utah, and Colorado at the ‘Four Corners’ ; area 314,311 sq km/121,356 sq mi; population (2010) 2,059,179; capital Santa Fe , the oldest capital city in the USA. New Mexico is known for its rich heritage and stunningly diverse landscapes – all the major biomes of the world, with the exception of the tropical rainforest, are found in the state. The state's most important river is the Rio Grande . The service industry and tourism are important elements in the economy of New Mexico, as are agriculture, mining, and the manufacture of electronic equipment. Major towns and cities include Albuquerque , Las Cruces , Rio Rancho , Roswell , and Farmington . The upper region of the Rio Grande was called Nuevo Mexico as early as 1561, becoming New Mexico after it was ceded to the USA…