The 2010 census revealed less than 105,000 inhabitants in Round Rock , Texas .
The 2013 census estimate places the population at 109,821.The city straddles both sides of the Balcones Escarpment , Texas State Historical Association a fault line in which the areas roughly east of IH-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 with little topsoil and higher elevations and which is part of the Texas Hill Country .
Round Rock, Texas