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South Texas Plains Main
Prehistoric Texas Main

Hunter-Gatherer Life along the Frio River
in the South Texas Brush Country

View looking northeast across the Frio River Valley from Skillet "Mountain," a locally prominent landscape feature, prior to the completion of Choke Canyon Reservoir. Photo by Bob Stiba.

The stage was set in the brush country of South Texas, where it is said that "everything sticks, stings, or stinks." When archeologists from several universities in Texas arrived to work along the Frio River in Live Oak and McMullen counties in the summer of 1977, we encountered all that and more. Merciless heat and humidity, biting and embedding bugs, thorny and stinging plants, rattlesnakes and drought. We had come to investigate the archeological evidence that would soon be inundated by Choke Canyon Reservoir. We sweated, swatted, and occasionally swore as we worked for months on end at many different archaeological sites, doing our part to see that something of the area's human past was salvaged before the waters rose. Along the way, we learned to appreciate many of the challenges that generation after generation of hunting and gathering peoples had successfully met in their homeland, the area often known today as the South Texas Brush Country.

Choke Canyon lies in the thick of the brushy heartland of the South Texas Plains. The region is semi-arid and warm to hot most of the year. Winters are normally mild, but when high humidity is coupled with a blustery blue norther, it can be bone-achingly cold. Hard freezes occur every few years, sometimes accompanied by ice storms, and snow is not unheard of. To modern visitors, the dense thickets of blackbrush, whitebrush, guajillo, prickly pear, and mesquite found over tens of thousands of acres create a seemingly hostile environment. In truth, the entire region is not covered by brush. Extensive brushy areas have been cleared over the past hundred years to create fields for farming and pastures for cattle grazing. Overall, the terrain is gently rolling, with broad, shallow river and stream valleys, such as those of the Frio River and San Miguel Creek, and low rugged valley walls. The creeks and rivers are lifelines on which animals and peoples have always depended.

Changing Historic Landscape

Today's South Texas Plains landscape is largely the product of the past 300 years of changes brought on by the arrival of, first, the Spanish-Mexicans coming north out of Mexico, and later the Anglo-Europeans moving in from the northeast. "Old timers" remembered a South Texas with considerably less brush even as late as the early 1900's. Nonetheless, our archeological evidence from Choke Canyon helped demonstrate that the thorn-covered species that now infest the region have been present for thousands of years. Since Ice-Age times, brush was always a part of the region's landscape, but in earlier times were more confined in their extent. Experts agree that the Spanish introduction of a host of Old World domestic animals—chief among them cattle, horses, sheep, and goats—and the rapid growth of their numbers over a relatively short time began the process of decimating native grasslands. Severe overgrazing of the original prairies and savannahs, coupled with a dramatic reduction of prairie fires, gave noxious brush species the upper hand and their rapid spread dramatically altered the complexion of the South Texas Plains. Certainly, too, the Spanish cattle and horses ate the beans, nuts, and seeds of mesquite, prickly pear, and other brush species and spread them far and wide in their manure.

The thickening spread of brush has had many harmful effects on south Texas. Perhaps the single most grievous impact, other than the loss of grasses, was in the drying up of seeps, springs, and creeks that once ran water. Woody vegetation soaks up tremendous amounts of water that, in prehistoric times, instead would have fed regional drainages, making surface water more dependable than in modern times. And brush alone cannot be blamed for all of the loss; wells and irrigation pumping lower the water tables as well. Sadly, as the result of combined factors, the landscape of south Texas has been changed forever in less than two centuries.

Prehistoric Landscapes and Resources

Looking back over the thousands of years of prehistoric time during which humans were active as hunter-gatherers in the Frio River valley, we must first appreciate the fact that their habitat was not as brushy and most of the time contained more sources of surface water. Grasses were thicker and grasslands were more extensive. All the brush species were present, but most were confined to, or at least concentrated within, thin-soiled rugged slopes, arroyos, and rocky hilltops, and were kept in check by fires and densely-matted grasses. The water courses were lined with thick woodlands that included large trees, such as live oaks, elms, pecans, and others.

Over the 13,000-year stretch of prehistory evidenced at Choke Canyon the landscape changed in response to climatic changes. The area lies along the continental boundary between relatively moist conditions to the east and extremely arid to the west. Through time, as it still does today, the climate of south Texas would have oscillated from tolerably wet to terribly dry. As today's ranchers know only too well, the region is prone to periodic drought cycles, some of them lasting only a few months, others lasting years. But most of us do not realize that dryer-than-average periods can also last for hundreds of years, as can wetter periods. During dry times, particularly prolonged periods, the grasslands and woodlands suffered, as did the supply of surface water and water-loving plants and animals. In wetter times it was the reverse. So do not imagine an idyllic and unchanging green and grassy prehistoric wonderland; it was and is an area prone to marginal conditions and shifts from green to brown.

photo of choke canyon slough
Physiographic map showing the location of Choke Canyon Reservoir. Adapted from Lynn et al. 1977, Figure 1, map drawn by Richard Hubbard. Enlarge to see original with legend. Enlarge image

Enlarge image = image can be enlarged

photo of brush country
Typical Brush Country of McMullen County near Choke Canyon Reservoir. Photo by Curtis L. Dusek. Enlarge image
photo of brush clearing
One of the methods used by landowners to clear the brush in the Choke Canyon area is to drag rail sections behind heavy chains. This effectively removes the brush to promote the growth of grass, but it sometimes has the unintended consequence of damaging shallow archeological sites. At other times, however, archeologists benefit from brush clearing. The Late Prehistoric bison butchering evidence at Skillet Mountain site was spotted after fresh exposure by chaining. Enlarge image
photo of tunas
Blooming prickly pear cactus along Old Highway 72, in the vicinity of Callaham, a small town now under the waters of Choke Canyon Reservoir. Enlarge image
photo of choke canyon slough
Sloughs or oxbow "lakes" form in former river channels abandoned by the meandering Frio River and its largest tributaries. After floods, these were natural fish traps that hunter-gatherers must have taken advantage of as the water slowly evaporated. Enlarge image
drawing of landscape

Schematic diagram across the Frio River Valley showing the major plant communities upon which prehistoric peoples depended.
Adapted from Jurgens 1980, Figure 29. Enlarge to see legend. Enlarge image

For hunter-gatherers, the coalescent valleys of the Frio, Atascosa, and Nueces rivers (near the aptly named town of Three Rivers) created a rich environment. Yes, dry periods were harder to survive than wet times, but compared to the upland areas of the South Texas Plains, the river valleys were always relatively resource-rich, even in hard times. The several hundred prehistoric sites found during archeological investigation of the Choke Canyon Reservoir on the Frio River attest to the suitability of this land in supporting ancient hunter-gatherers throughout prehistoric times.

Local geologic formations, such as upland gravel deposits and gravel bars along rivers and streams, provided ample supplies of chert and quartzite, the raw materials needed for the manufacture of a variety of stone tools. Outcrops of sandstone and tuffaceous siltstone provided rocks used in making grinding implements. They were also used as boiling stones and as heating elements in earth ovens and hearths.

Though plant remains are poorly preserved in the local archeological record, we can safely assume (on the basis of ethnohistoric data and findings in the Lower Pecos) that trees and plants provided abundant wood and fiber used for shelter components, tools, tool parts, baskets and other woven containers, cordage, nets, and mats. Clothing and footwear, such as they were, were made from animal hides and woven plant fibers. Warm cloaks and blankets were made of twined and woven rabbit furs or the fur-covered hides of deer and bison. These materials and technologies insulated people from the climate and aided in the extraction and processing of the wild foods that provided sustenance.

There is no evidence or reason to believe that prehistoric people in the Choke Canyon area, or anywhere in the South Texas Plains, produced any of their own food through farming or raising livestock. That being the case, what wild plant and animal foods were available to prehistoric people along the lower reaches of the Frio River? The brush species, in modern times a blight on the countryside, were important food providers to prehistoric people. For instance, mesquite trees have a nutritious bean that was ground up to make a protein-rich flour for making breads and gruels.

In the spring, the prickly pear cactus provided tender new-growth (and spineless) leaf pads that could be eaten raw or baked (known in Spanish as nopalitos). In the summer, the prickly pear yielded fruits that had both a sweet flesh and protein-rich seeds (called tunas in Spanish). Judging from early Spanish accounts, prickly pear was a major staple.

photo of landscape
View across the wooded bottomland along the Frio River. Enlarge image
photo of choke valley gravels
Upland gravels deposits are common along the "valley wall" or upland edge of the Frio Valley. These were heavily used by prehistoric peoples as source areas for tool-making stones. Enlarge image
choke canyon frio
The Frio River during a slight rise. Muddy water is more common today as a consequence of land-clearing and erosion. The river is spring-fed at its headwaters in the Balcones Canyonlands, some 200 miles upstream from Choke Canyon. Enlarge image
photo of tunas
Ripe tunas or pears of the prickly pear cactus were likely a major staple, as attested by Cabeza de Vaca in the early 1530s. Enlarge image
photo of fruits and seeds
The brushy plants of the Choke Canyon are yield many kinds of edible fruits, beans, and seeds. Enlarge to see identifications. Enlarge image
photo of persimmon
Texas persimmon yields ample fruits, quite tart, but edible and useful for mixing with other foods when it ripens in late summer. Enlarge image

Other edible fruits would have included agarita, spiny hackberry, yucca, tasajillo, and persimmon. Walnuts, pecans, acorns, grass seeds, and a variety of other seeds, beans, and nuts were also seasonally available. Shrubs and forbs growing along the river and in nearby upland prairies provided edible blossoms and foliage and, most importantly, a variety of tubers, bulbs, and roots (collectively, geophytes) that could be eaten raw or baked to make them fit for human consumption. These were important sources of carbohydrates, especially the geophytes, which were among the few plant resources available in the winter and early spring.

Meat foods and animal products used to make tools, ornaments, clothing, and other coverings included many different land and water animals. Out of the Frio River and its major stream tributaries came fish such as freshwater drum, gar, catfish, bass, and minnows. Aquatic turtles, snakes, mussels (freshwater clams), and the occasional alligator were also taken. On land, the animal spectrum hunted, netted, trapped, or hand-caught ran from the mighty bison down to the lowly field mouse. In descending size order, the mammals included bison, whitetail deer, antelope, mountain lions, wolves, javelinas, bobcats, coyotes, raccoons, opossums, skunks, jackrabbits, cottontails, squirrels, rats, and mice. Of those, deer, rabbits, and rodents were the most dependable sources of meat. Bison herds came through the region only periodically when the grasslands of their regular habitat of the Southern and Central Great Plains were less attractive owing to drought and perhaps intensive hunting.

upland canyon
The uplands surrounding Choke Canyon have their own sets of resources. Photo by Curtis L. Dusek showing the mouth of a McMullen County "canyon." Enlarge image
photo of a buffalo
This buffalo (bison) raised near Tilden, Texas would find slim natural pickings in today's landscape. Photo by Bob Stiba. Enlarge image
photo of javelinas
Archeological evidence (bones) showed that javelinas were hunted and eaten by Late Archaic times in the Choke Canyon area. Photo by Bob Stiba. Enlarge image
photo of field mice
Field mice were probably regular items on the prehistoric dinner plate. Evidence from the dry caves of the Lower Pecos suggest that these were often eaten whole, skin, bones and all. Enlarge image
photo of a bird's nest
Bird nests (this one hidden by prickly pear) were sources of hunter-gatherer delicacies.Photo by Bob Stiba. Enlarge image
photo of a lizard
Lizards are another hand-caught food source. Photo by Bob Stiba. Enlarge image
photo of a rattlesnake
Western diamond back rattlesnakes can be dangerous, but they were on the Choke Canyon diet. Photo by Bob Stiba. Enlarge image

Reptiles, such as lizards, frogs, terrestrial snakes, and tortoises were all taken. Turkeys, quail, doves, ducks, and other birds were hunted and trapped. The eggs of all birds, turtles, and snakes would have been collected and eaten with enthusiasm when found. Even land snails, especially the genus Rabdotus, were gathered, roasted (steamed or boiled), and eaten. Insects and their larvae were important foods at certain times of the year. Grasshoppers and cicadas are especially plentiful at times and likely contributed important proteins and fats to the hunter-gatherer diet.