The Oregon-California Trails Association (OCTA) and the Southern Trails Chapter of OCTA present the "Yuma Historic Trails and the Yuma Crossing" Symposium. The focus is on Yuma and its role as the primary crossing of the CO River and will include looks at the American Indian, Spanish, Mexican, and U.S. eras, including local tribes, the Alarcon (Coronado) Expedition of 1540, Spanish missions, Juan Bautista de Anza, the Mormon Battalion, 49ers on the Southern Route, the Butterfield Stage, military presence, and the Old Spanish Trail Hwy, among others.