San Antonio serves as the seat of Bexar County. Recent annexations have extended the city's boundaries into Medina County and, though for only a very tiny area near the city of Garden Ridge, into Comal County. Due to its placement, the city has characteristics of other western urban centers in which there are sparsely populated areas and a low density rate outside of the city limits. San Antonio is the center of the San Antonio–New Braunfels Metropolitan Statistical Area. Commonly referred to as Greater San Antonio, the metropolitan area has a population of 2,454,061 based on the 2017 US Census estimate, making it the 24th-largest metropolitan area in the United States and third-largest in the state of Texas. Growth along the Interstate 35 and Interstate 10 corridors to the north, west and east make it likely that the metropolitan area will continue to expand.