Fort Yuma California, circa 1875, lithograph. 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 1000 feet wide in one small point. Later military expeditions that crossed the Colorado River at the Yuma Crossing include Juan Bautista de Anza , the Mormon Battalion and the California Column . Following the establishment of Fort Yuma, a town sprang up on the New Mexico Territory side of the Colorado. The townsite was duly registered in San Diego, demonstrating that both banks of the Colorado River just below its junction 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.