Santa Ana is the county seat and most populous city in Orange County, California, and the 53rd-most populous city in the United States with a 2007 estimated population of 339,555. (The California Department of Finance puts the city's 2009 estimated population at 355,662. ) Founded in 1869, Santa Ana is located in Southern California on the Santa Ana River, 10 miles (16 km) away from the California coast. The city is part of the Los Angeles–Long Beach–Santa Ana metropolitan area which, according to the U.S. Census Bureau, is the second largest metropolitan area in the U.S. , with almost thirteen million people. According to the 2000 U.S. Census, of U.S. cities with more than 300,000 people, Santa Ana is the 4th-most densely populated, behind only New York City, San Francisco, and Chicago, and slightly denser than Boston. Santa Ana lends its name to the Santa Ana Freeway, which runs through the city. It also shares its name with the nearby Santa Ana Mountains, the Santa Ana Watershed, and the infamous Santa Ana Winds, which historically have fueled seasonal wildfires throughout Southern California. The current Office of Management and Budget (OMB) metropolitan designation for Santa Ana and the Orange County Area is "Santa Ana-Anaheim-Irvine, CA".