There are two explanations for the origin of the name Arizona: either from árida zona, meaning arid zone in Spanish, or from a Spanish word of Basque origin that means The Good Oak.
California

To find the origin of California, we should recall the name of a fictional island country mentioned in Las Sergas de Esplandián, a popular Spanish chivalric romance written by Garci Rodríguez de Montalvo, which was published in 1510.