[5] The city straddles the Balcones Escarpment,[6] 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 with little topsoil and higher elevations and which is part of the Texas Hill Country.

In a CNN article dated July 1, 2009, Round Rock was listed as the second-fastest-growing city in the country, with a population growth of 8.2% in the preceding year.

The area's earliest known inhabitants lived during the late Pleistocene (Ice Age), and are linked to the Clovis culture around 9,200 BCE based on evidence found at the much-studied Gault Site, midway between Georgetown and Fort Cavazos.

[13] One of the most important discoveries in recent times is the ancient skeletal remains dubbed "the Leanderthal Lady" because of its age and proximity to Leander, Texas.

[14] The site is 4 miles (6 km) west of Round Rock and was discovered by accident by Texas Department of Transportation workers while drilling core samples for a new highway.

Prehistoric and Archaic period "open occupation" campsites are also found throughout the county along streams and other water sources, including Brushy Creek in Round Rock and the San Gabriel River in Georgetown, 10 mi (16 km) north.

[15] These archeology dig sites show a much greater volume United States evidence of Archaic period inhabitants based on relics and flint tools recovered from burned rock middens.

Apparently, small numbers of Kiowa, Yojuane, Tawakoni, and Mayeye Native Americans lived in the county at the time of the earliest Anglo settlements.

One famous immigration route passed through Round Rock and is called the "Double File Trail" because the path was wide enough for two horsemen to ride side-by-side.

[18] After the Civil War, Jesse Chisholm began moving cattle from South Texas through Round Rock on the way to Abilene, Kansas.

[20] Downtown Round Rock was the site of a historic gunfight and subsequent capture (and death) of the 19th-century American train robber Sam Bass,[21] by the Texas Ranger Division on July 19, 1878.

The bronze sculptures of four steers with pioneer woman Hattie Cluck and her son, Emmitt, were commissioned by the city through donations from Round Rock residents.

Following the end of the American Civil War, a group of Confederate veterans held a reunion in Georgetown on August 27, 1904, for the old settlers of Williamson County and their descendants.

Highway Commissioner DeWitt Greer called for the "interregional" highway to go through Taylor on its way from Dallas to Austin, but some Taylor leaders and other citizens fought the idea, worried about the possibility of cutting farmers off from all or part of their fields, traffic noise, damage to country life, loss of farmland, and unwanted right-of-way acquisition—it was proposed to be an astounding 300 feet (90 m) wide, unheard of before this time.

[33] Due to the heavy lobbying, and not wanting to antagonize Taylor, the highway was built along the edge of the Balcones Fault line, running through Round Rock.

[34] The Interstate eventually made Round Rock into a viable and vibrant commercial center, while Taylor withered with the decline of the cotton industry.

Today, it is a minor, modest town with a smaller population, while Round Rock has thrived and rapidly grown into the largest city in the county, attracting Dell Computer and major retail centers.

[19] Round Rock has more than 20 major employers[10] including: Cerilliant Corporation, Cintas, Dell, Dresser, Emerson Process Management, Hospira, IKEA, KoMiCo Technology Inc., Round Rock Premium Outlets, Prudential Overall Supply, Sears Customer Care, Texas Guaranteed Student Loan Corp, Tekscend Photomask, and TECO-Westinghouse.

[48] As of 1999, approximately half of the general fund of the City of Round Rock originates from sales taxes generated from the Dell headquarters.

[53] The major-retailer center includes the Simon Property Group's Premium Outlets Mall, as well as numerous other retail stores and restaurants.

Round Rock opened a free public skate park in 2007[56] behind the Clay Madsen Recreation Center on Gattis School Road.

MUDs are typically formed by a residential developer as a means to install utilities and roads to a project when a city is not ready or able to provide them.

The MUD provides a wide range of city-like services including parks and recreation, full utilities, road maintenance and a Home Owner's Association.

Another similar but somewhat smaller MUD in Round Rock's is Fern Bluff Municipal Utility District[68] in the Wyoming Springs area of town.

[70] The area covers 110 square miles (280 km2) encompassing high-tech manufacturing and urban retail centers, suburban neighborhoods, and farm and ranch land.

The annual dropout rate for students in grades 7–12 is 1.1%, and more than 77% of the district's graduating seniors take the SAT and ACT college entrance exams, scoring well above state and national averages.

The concept was envisioned as a way to lure colleges and universities to jointly provide education, training, and degree opportunities on part-time and full-time bases.

The center used various empty facilities around town, and many of the initial training programs were targeted to help educate students for work at local companies, such as Dell, which had specialized needs.

In 2008, an educational campus and the first RRC building—the Avery Building—was opened through the combined efforts of Texas State University, Austin Community College, and Temple College in order to provide a broader range of educational opportunities, specialized training, and varying degree programs including post graduate degrees.

[75] In August 2010, Austin Community College's largest campus to date opened adjacent to the Texas State University center.