Prior to the adoption of its name for a U.S. state, Arizona was traditionally defined as the region south of the Gila River to the present-day Mexican border, and between the Colorado River and the Rio Grande. It encompasses present-day Southern Arizona and the New Mexico Bootheel plus adjacent parts of Southwestern New Mexico. This area was transferred from Mexico to the United States in the Gadsden Purchase of 1853. Mining and ranching were the primary occupations of traditional Arizona's inhabitants, though growing citrus fruits had long been occurring in Tucson.