Edwards Plateau: A Geologic Region at the Heart of Texas

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Tony Maples Photography


Though most know of the Texas Hill Country, the Edwards Plateau is less familiar. This geologic region of the state includes the Hill Country on its eastern edge, but that’s not the only part of this area. This plateau’s formation has shaped the cultural and natural history of the state, and people in the area have also changed the natural flora and fauna of the plateau.

Where is the Edwards Plateau?

Edwards Plateau in Texas

Photo: Wikimedia Commons

Stretching from the Balcones Escarpment, which marks the eastern edge of the Hill Country, out to the deserts of west Texas, this region takes up much of the state. This area, though higher than the Gulf Coast, does not have a consistently hilly terrain. The hills of the Hill Country formed when softer limestone eroded away from the harder granite and other rock beneath the surface. This wear creates the distinctive hills of the region, but toward the west of the plateau, drier weather keeps erosion to a minimum, resulting in a flatter landscape.

Flora and Fauna

Cedar trees are common in the Hill Country and Edwards Plateau

Photo: Pixabay/I_Take_Phone_Pictures

Before the area became settled, grassland reigned across the plateau. Grass fires would regularly rejuvenate the landscape, burning seedling trees, allowing the grass to flourish. Without competition for light, water, and minerals from trees, the grass extended across central Texas. This provided an ideal place for antelope. Today, however, changes to the natural flora and fauna have resulted in a scrub forest with too many deer for the area to properly support. Hunters help to keep this population in check each fall, but deer rarely appeared on the plateau when it was a grassland.

How People Have Changed the Region

The plants and animals that live in the Edwards Plateau have been influenced by farming and ranching practices

Photo: Wikimedia Commons

Over time, people have filtered into the Edwards Plateau. Since the 1800s, permanent settlements appeared in an area where native tribes only passed through. The settlers lived on farms and ranches, and their animals changed the native plants in the area. By browsing on softer grasses and plants, harder to eat forage plants, like cedar, took over an area that was originally a grassland. The settlers also prevented fires that encouraged the growth of the savannah and prevented the growth of trees, this resulted in grasslands converting into scrublands with short trees throughout the region.

Geology of the Edwards Plateau

Edwards Plateau as seen from space

Photo: Wikimedia Commons

The rocks beneath the plateau directly affect the landscape. Limestone, found in much of the Texas Hill Country, is a soft, easily dissolved rock, and over time, rainwater wears down limestone until it washes away, exposing granite beneath. These hills and surrounding valleys of the Hill Country are a direct result of limestone washing away. But go further west on the plateau, and you enter a drier, more desert-like environment with less rain. Less rain means less erosion and a flatter landscape until you reach the mountains of west Texas.