Springfield is the third largest city in the U.S. state of Missouri. It is the county seat of Greene County. On July 1, 2009, the estimated population was 157,630. The Springfield Metropolitan Area, population 430,900, includes the counties of Christian, Dallas, Greene, Polk and Webster. Springfield’s nickname is The Queen City of the Ozarks. It is also known as The Cultural Center of the Ozarks, The Gateway to the Ozarks, and The Birthplace of Route 66.