Greater Sacramento straddles two key regions of California, the Central Valley and the Sierra Nevada mountains and is overlapped by the cultural influences of three areas, the Bay Area, Eastern California and Northern California. An increasing phenomenon taking shape in Greater Sacramento is growth of urban sprawl as Sacramento and its metropolitan area continue to expand. The growth is due in part to first, higher costs of living in the Bay Area which have caused commuters to move as far as Yolo and Sacramento counties and more recently, growth and rising living costs in the core of Sacramento, building up more areas in the surrounding counties for commuters. Sacramento is the largest city in the metropolitan area, home to approximately 500,000 people, making it the sixth-largest city in California and the 35th largest in the United States. It has been the state capital of California since 1851 and has played an important role in the history of California. Although it did not become the financial and cultural center of Northern California, titles that were given to San Francisco, Sacramento became the largest transportation hub of not only Northern California, but also the West Coast following the completion of the First Transcontinental Railroad. Sacramento today continues to be one of the largest rail hubs in North America, and its rail station is one of the busiest in the United States. In 2002, Time Magazine featured an article recognizing Sacramento as the most diverse and integrated city in America. Government (state and federal) jobs are still the largest sector of employment in the city and the city council does considerable effort to keep state agencies from moving outside the city limits. The remainder of Sacramento County is suburban in general with most of the working population commuting to Downtown Sacramento and with a smaller proportion commuting all the way to the Bay Area.