Berger Bluff is a sandy bluff, 8.7 meters high, on the Goliad County side of Coleto Creek west of Victoria. The entire bluff (now inundated by Coleto Creek Reservoir) apparently has stratified prehistoric Indian occupations, although the middle 4.5 meters has never been sampled. The upper deposits were excavated in 1977, 1979, and 1983, the lower deposits in 1979–80. Most excavation in the upper deposits was concentrated in a three-by-four-meter block about 2.5 meters deep. Here, chiefly in the upper forty-five centimeters, Late Prehistoric artifacts and animal remains from the Toyah Phase (radiocarbon dated elsewhere in south Texas at a.d. 1300–1600) and the Austin Phase (about a.d. 800–1300) were found. Toyah Phase artifacts include Perdiz arrow points and preforms, a few pieces of plain bone-tempered pottery, a core, and preforms for thinned bifaces. Austin Phase artifacts include Scallorn arrow points, Darl points, thinned bifaces, and a core. Snail and freshwater mussel shells are found throughout but are especially abundant in the Austin Phase midden, where at least seven species of mussels and nine of land snails were found. Most of the mussel shells are atypically small, suggesting that frequent washouts due to flooding of Coleto Creek may have prevented mussels from reaching maturity. Vertebrates (about four dozen kinds) are also abundant in both of these Late Prehistoric phases and include gar, white-tailed deer, pocket gopher, eastern mole, eastern cottontail, cotton rat, soft-shell turtle, wood rat, red-eared turtle, jackrabbit, opossum, Western diamondback rattlesnake, bison, and many other kinds of mammals, reptiles, birds, and fish.
Below these Late Prehistoric occupations, samples were taken from two meters of Archaic sediments. The upper part, apparently Late Archaic, contains a few Ensor (dated elsewhere at about 200 b.c. to a.d. 600) and Morhiss dart points, along with other thinned bifaces, biface preforms, cores, hammerstones, ground sandstone, modified flakes, chipping debris, snails, and mussel shells. Very little animal bone survives in these older deposits, only white-tailed deer and fish having been recognized. Features of probable Archaic age include two small clusters of fire-cracked sandstone and a small pit with dark fill. The lower part of the excavation block has sparse cultural debris and mussel and snail shell of unknown age, perhaps Middle Archaic.
Separated from the bottom of the bluff-top excavation block by 4.5 meters of unexcavated sediments and exposed at the foot of Berger Bluff in the form of a prominent ledge or bench were 2.25 meters of cyclically bedded early Holocene Coleto Creek floodplain deposits, apparently cemented by alkaline groundwater from a nearby spring (though no actual spring conduit was located). By the Late Prehistoric, the creek began rapidly incising the several meters of floodplain deposits that had accumulated, leaving a resistant ledge when it encountered these locally cemented deposits. The weighted average of eight radiocarbon assays from the bench deposits is 9564 ± 43 b.p. (b.p. = before a.d. 1950), but it is likely that the span of time represented by the bench deposits is much longer than implied by this single average age.
The bench excavations, consisting of eight one-square-meter units of varying depth, produced sparse cultural evidence: chipping debris (including that from a chipping area), cores, a few introduced pebbles, a small triangular biface reject, and three cultural features (two small pits and the hearth mentioned above), but no diagnostic artifacts. These deposits, however, provide an early Holocene paleoenvironmental record unequaled in the region. The record suggests that by about 8000–10000 b.p., the upland landscape between the drainages in this part of the coastal plain had already taken on an essentially Holocene biotic composition. Coleto Creek, however, retained vestiges of its cooler and wetter Pleistocene ecology and served as a refuge for fauna (especially invertebrates), and possibly for flora as well.
Three species of very small snails now extirpated in South Texas were extracted by flotation and identified. Valvata tricarinata, an aquatic snail now ranging from Oklahoma or Nebraska north to Canada, prefers such deep, cool water as Nebraska springwaters (15° C; modern Coleto Creek water ranges from 17° C in February to 30° in July). Pomatiopsis lapidaria, an amphibious snail, prefers marshes with grass, sedges, and cattails in the eastern United States and plains as far south as Kansas. Gastrocopta armifera is a land snail that in North Texas lives in decaying logs and under leaf litter. Altogether over thirty taxa of snails, many of them microscopic in size, were identified in the bench deposits; some species tolerate well-drained open woodlands or savanna habitats, but many inhabit leaf litter in wooded floodplains or are wetland or aquatic species. In contrast to the upper deposits, few mussel shells were found in the lower. Most were Amblema plicata valves lying flat on a buried floodplain surface. All of the bench mussels, however, were conspicuously larger than their Late Prehistoric counterparts from the upper deposits, a fact that suggests flash flooding was not yet common in the very early Holocene. Particle-size, carbonate, and organic-carbon analyses of a column of twenty-eight sediment samples suggest that the early Holocene creek was very different from its modern counterpart. Flowing in a broader, flatter, more heavily vegetated floodplain, it was narrower, deeper, more sinuous, and muddier than the modern creek, and lacked its contemporary propensity for flash flooding.
Next to the small hearth already mentioned, a remarkable deposit of several thousand bone fragments from small animals was found. Some of the bone was found on the hearth surface, but only a few fragments were charred. The deposit consists of the remains of various small animals: eastern mole, frog, gopher, smallmouth salamander, small perching birds, pocket mouse, fish (perch-sized), prairie vole or pine vole, kangaroo rat, least shrew, rabbit, wood rat, field mouse, northern grasshopper mouse, toad, small snakes, and lizards. A juvenile rabbit is the largest animal. Nothing approaching this density of bone was found elsewhere in the bench deposits. Laboratory extraction of lipids from sediment samples showed that the hearth was much higher in fatty acids, especially those characteristic of animal tissue. Extreme clustering of the bone indicates the fauna was concentrated in the digestive tract of a predator. At least two distinct assemblages occur: aquatic-riparian species that probably collected in or around the creek and spring itself; and a sandy grassland (upland or floodplain) assemblage featuring fossorial rodents. Two behavioral groups are evident: the first, active both day and night (usually living in burrows, sometimes in thickets or debris), would be vulnerable to all kinds of predators. The second is nocturnal and fossorial. Venturing out at night to forage, these would be vulnerable to owls but not hawks, and especially to humans, since they are confined to burrows during the day. The mole, for example, rarely ventures above ground and is only occasionally taken by owls. In general, this is a cryptic or reclusive fauna, composed of small and inconspicuous animals with a wide range of adaptations; aquatic, aerial, terrestrial, and terrestrial-fossorial habits are represented, indicating that the Berger Bluff predator foraged successfully in a diversity of habitats and coped with a diversity of prey habits. This kind of flexibility is distinctly human. The vertebrate fauna is typically Holocene, although there are a few species not found in the immediate vicinity today.
The concentration of this bone deposit suggests fecal remains. The diversity of prey behaviors and habitats, the extensive breakage (indicating mastication), proximity to the hearth, and partial charring of some of the bones all seem to indicate the predator was human. The deposit may well represent a very early broad-spectrum foraging pattern exemplified at Baker Cave and Horn Shelter No. 2 (Texas), Medicine Lodge Creek (Wyoming), the Stigenwalt site (Kansas), and perhaps Shawnee Minisink (Pennsylvania). Similar prey were often captured by task groups of women and children in ethnographically known societies.