Yuma is a city in and the county seat of Yuma County, Arizona, United States. It is located in the southwestern corner of the state, and the population of the city was 93,064 at the 2010 census, up from the 2000 census population of 77,515.Yuma is the principal city of the Yuma, Arizona Metropolitan Statistical Area, which consists of Yuma County. According to the United States Census Bureau, the 2014 estimated population of the Yuma MSA is 203,247. More than 85,000 retirees make Yuma their winter residence.HistoryThe area's first settlers for thousands of years were Native American cultures and historic tribes. Their descendants now occupy the Cocopah and Quechan reservations.In 1540, Spanish colonial expeditions under Hernando de Alarcon and Melchior Diaz visited the area and immediately recognized the natural crossing of the Colorado River as an ideal spot for a city. The Colorado River narrows to slightly under 1,000 feet wide in one area. Military expeditions that crossed the Colorado River at the Yuma Crossing include Juan Bautista de Anza (1774), the Mormon Battalion (1848) and the California Column (1862).