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, AZ Metropolitan Statistical Area, which consists of Yuma County. According to the United States Census Bureau, the 2012 estimated population of the Yuma MSA is 200,022, though more than 85,000 retirees make Yuma their winter residence.
The area's first settlers were Native American tribes whose descendants now occupy the Cocopah and Quechan reservations. In 1540, expeditions under Hernando de Alarcon and Melchior Diaz visited the area and immediately saw the natural crossing of the Colorado River as an ideal spot for a city, as the Colorado River narrows to slightly under 1,000 feet wide in one small point. Later 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).
Following the establishment of Fort Yuma, a town sprang up on the New Mexico Territory (now Arizona) side of the Colorado. The townsite was duly registered in San Diego, demonstrating that both banks of the Colorado River just below its confluence with the Gila were recognized as being within the jurisdiction of California. The county of San Diego collected taxes from there for many years. The town, initially called Colorado City, was renamed Arizona City in 1858. The city was almost completely destroyed by the Great Flood of 1862 and had to be rebuilt on higher ground. It took the name Yuma in 1873.
The Southern Pacific Railroad bridged the river in 1877, and acquired George Alonzo Johnson's Colorado Steam Navigation Company, the only steamboat company on the river. Yuma became the head of navigation on the river, ending the need for Port Isabel, which was abandoned in 1879.