Southern California is a megaregion, or megapolitan area, in the southern area of the U.S. state of California. Large urban areas include the Los Angeles Metropolitan Area, the Inland Empire, and Greater San Diego. The region stretches along the coast from about Santa Barbara to the United States and Mexico border, and from the Pacific Ocean inland to the Nevada and Arizona borders. The heavily built-up urban area stretches along the coast from Ventura, through the Greater Los Angeles Area, to San Diego. Southern California is a major economic center for the state of California and the United States. Southern California's population encompasses eight metropolitan areas, or MSAs: the Los Angeles metropolitan area, consisting of Los Angeles and Orange counties; the Inland Empire, consisting of Riverside and San Bernardino counties; the San Diego metropolitan area; the Bakersfield metropolitan area; the Oxnard–Thousand Oaks–Ventura metropolitan area; the Santa Barbara metro area; the San Luis Obispo metropolitan area; and the El Centro area. Out of these, three are heavy populated areas: the Los Angeles area with over 12 million inhabitants, the Riverside-San Bernardino area with over 4 million inhabitants, and the San Diego area with over 3 million inhabitants. For CSA metropolitan purposes, the five counties of Los Angeles, Orange, Riverside, San Bernardino, and Ventura are all combined to make up the Greater Los Angeles Area with over 17.5 million people. With over 22 million people, southern California contains roughly 60% of California's population.