"Realistic observers of their northern province, the Spaniards always spoke of "The Californias"—Baja California and Alta California; Lower California and Upper California; New California and Old California. Later, still more Californias, more regional entities, were distinctly etched: the Mother Lode Country, known to the natives as Superior California; the Delta district; the Redwood Empire; the great Central Valley; and the Desert Country. While most of these regions and sub-regions are clearly delineated, none is more sharply defined, geographically and socially, than the area now known as Southern California."