MAP OF CENTRAL TEXAS: Showing Its Principal Geologic-Geomorphic Provinces

The large circle (see #1) on the map above outlines the lovely, laid back and friendly Hill Country. It is Texas' single most appealing physiographic province, encompassing approximately 16,000 square miles with an average diameter of about 125 miles. It serves as Texas principal playground. Horseshoe Bay ("HSB") is located in its northeast quadrant (see arrow), being about 50 northwest of Austin and 80 north of San Antonio. Both of these major cities are located on the province's outer margin and both are bisected by the regional Balcones Fault System (see #6), which extends across Texas from northern Mexico into southern Arkansas.

The long dormate Balcones Fault, which has over 1,000 feet of down to the coast vertical movement, is one of the most dominate geologic/geomorphic features in Texas. It fractured the State into two principal parts -- the Gulf Coastal Plain (see # 7), located to the Fault's souIth and east, and the much higher upthrown terrain as best represented by the Edwards Plateau (see # 5). It was active for a few million years beginning about 20 million years ago and its movement initiated a period of intense headland/downward erosion carried out by the pre-existing drainage system. The on-going process has produced what we know today as the Hill Country, typified by the following: a) flat-lying, chalky, very fossiliferous, whitish limestone strata of Early Cretaceous age; b) sharply incised valleys having up to 200 feet of local relief, especially along its outer margins and primary tributraries; c) Live Oaks and Junipers, d) an abundant variety of wildlife featuring cottontail deer and wild turkey; and e) crystal clear spring fed creeks.

Highly folded and faulted Paleozoic and pre-Cambrian rocks associated with the domal shaped Llano Uplift (see #2) stand exposed in the northern Hill Country's central sector. Paleozoics --typically grayish Ordovician and Mississippian limestone strata, the latter (Marble Falls Limestone) being the hardest rock in Texas -- generally occupy the Uplift's outer margin, surrounding older pinkish/reddish-orange igneous (granites) and dark gray metamorphic rocks of pre-Cambrian age. Where these rocks outcrop is referred to as the Central Mineral Region (see #3). The metamorphics are 1.2 to 1.3 billion years in age and are the oldest rocks that outcrop in Texas.

These so-called basement rocks are associated with the outer margin of the ancestral North American continent. Roughly 1.1 billion years ago, an ancestral drifting continent crashed into North America, compressing our continent's margin into a 20,000+ feet high mountain range built in part by the crash-induced intrusion of huge granite plutons such as Enchanted Rock, which arose finger-like from molten depths and dot our area.

The northern 2/3rds of the Hill Country is drained by the Colorado River System and has been dating back to the regions's second round of continental margin mountain building, which occured during the Permian-Triassic. The Canyon of the Colorado at Marble Falls was first carved during this time period, making it 50 times older than the Grand Canyon. During the mid-1900s, Texas built a system of six lakes on the Colorado, naming them the Highland Lakes (see #4). Portions if not all of the four uppermost lakes (in descending order: Buchanan, Inks, LBJ, Marble Falls) extend into the Llano Uplift area.

The "Sweet Spot of Texas" is a locale in central Texas where the State's four most favored contiguous provinces overlap. Few understand what it is that seems to magically draw such a major portion of Texas' residents to this small, readily mapable, 250 square mile area. It's not that HSB Resort and its five 4.5-star golf courses is by itself such a major draw. It's not just the colorful rock outcrops of the Central Mineral Region. It's not just the freshness of the newly-carved Hill Country and its sparkling clean spring-fed creeks. It's not just Lake LBJ, the country's largest constant-level lake with such extraordinary water sports, being America's lake of choice for those that know. It's not the exceptionally interesting, massively contorted rock formations of the highly folded and faulted Llano Uplift. It's not the spiritual heritage that one senses coming from those who came before, dating back thousands of years.

The clearly unmatchable area has its unique appeal simply because its where one can soak up the best in Texas -- the Hill Country, Highland Lakes, Llano Uplift and Central Mineral Region -- all at once! And without question, the best place to do that is at HSB, ranked #1 among "America's Premier Vacation Venues" (NEW YORK TIMES, May 26, 2008) and #4 regarding "Where America's Money Is Moving" (FORBES.COM, June 16, 2010).

Though we strive for accuracy in our reporting, we do not guarantee it. In particular, data can get out of date, so check things out before acting.