Round Rock is a city in the U.S. state of Texas, in Williamson County, which is a part of the Greater Austin metropolitan area. Its population was 99,887 at the 2010 census. The city straddles the Balcones Escarpment, a fault line in which the areas roughly east of Interstate 35 are flat and characterized by having black, fertile soils of the Blackland Prairie, and the west side of the Escarpment, which consists mostly of hilly, karst-like terrain... Show more

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