St. Mary's Hall Site

By: Thomas R. Hester

Type: General Entry

Published: December 1, 1995

The St. Mary's Hall Site is located on the property of St. Mary's Hall, a private school in northern San Antonio. The archeological deposits are situated on a colluvial downslope of Salado Creek, about thirty-five meters east of the present channel. This is one of the highest points (at 760 feet above mean sea level) in the Salado Creek drainage. Most of the buried deposits are on at the base of the hill slope, on a narrow flat area atop an eastern bluff of Salado Creek. The archeological remains first came to light in 1972, when a house was constructed just outside the southern boundary of the St. Mary's Hall property fence (this turned out to be the southern end of the site). Construction workers turned up large numbers of Indian artifacts, and many local relic collectors dug (in an uncontrolled fashion) at the site in 1972–73. One of their collections contained a large number of Paleo-Indian projectile points, as well as other chipped-stone artifacts from the Archaic and Late Prehistoric periods. As a result of the ongoing site destruction and the cultural materials revealed, the newly formed Southern Texas Archaeological Association undertook a program of site investigation on the St. Mary's Hall property immediately to the north of the looted area. This was designed as a "salvage" operation, an effort to see if the site continued onto the St. Mary's Hall property, to ascertain the depth of the deposits, and to try to evaluate the cultural stratigraphy that had been lost to the looting done on the adjacent property.

The STAA excavations took place in 1974–75. The surviving portion of the site was found to be forty-five meters long (north to south) and thirty-five to forty meters wide (east to west). Much of the area was found to have shallow deposits, with mixed cultural remains. However, at the northern end of the site, an extensive midden was found, an area twenty meters long and twelve to fifteen meters wide. The depth of these materials was about one meter. Excavations revealed extensive Middle and Late Archaic artifacts, with the occupation continuing into Late Prehistoric times. Beneath the midden, a zone of caliche gravels was encountered, and within this, several Paleo-Indian points of the Plainview type were found. STAA fieldwork was then halted, so that future research could be carried out to expose what appeared to be a Plainview occupation.

In summer 1977, the University of Texas at San Antonio conducted a summer archeological field school at the site, under the direction of T. R. Hester. The investigations were designed to expose large portions of two areas where Paleo-Indian artifacts had been found by the STAA. One area, Area B, had yielded a Folsom point; its excavation indicated that no Folsom occupation was present and that most of the area had been destroyed by an ancient erosional cut, or gully. In Area A, where the Plainview points had initially been found, an open-area excavation was laid out, involving a "block" of twelve two-meter-square units. The upper deposits, or midden, containing Late Prehistoric and Archaic materials was dug in ten-centimeter arbitrary levels. At about sixty-five to seventy-five centimeters below the surface, near the "transitional gravels" (a stratigraphic unit comprised of brownish soil and caliche gravels), arbitrary levels were switched to five centimeters in thickness; this was continued into the "gravels" in which the Plainview component was uncovered. The "transitional gravels contained several late Paleo-Indian projectile points (Golondrina, Angostura), alone with a few Early Archaic points (such as the Uvalde or Gower type).

The gravels constituted the lowest stratigraphic unit, composed of yellow caliche nodules and weathered bits of limestone; geomorphologists described it as having been formed by colluvial slopewash. Within the gravels in the northern part of the excavation, ball-like caliche conglomerates were sometimes found. Their geologic origin is obscure, but they shrink and swell and caused problems with artifact patterns in that area (e.g., a biface would sometimes be found in a vertical position). The lithic assemblage attributable to a Plainview occupation was found fifteen-twenty centimeters beneath the top of the gravels zone. These materials were distributed in an area eight meters north-south and six meters in width (forty-eight square meters). Plainview point fragments were clustered in the central part of this area. Altogether, several hundred chipped-stone artifacts were found. Many of these can be classified as debitage or waste flakes and the cores from which they were struck. Other lithics included trimmed or edge-modified flakes, steep-bitted unifaces (end scrapers), a large bifacial Clear Fork tool, a heavily-used chopper, and numerous bifaces (preforms) representing Plainview points in various stages of manufacture. There were no distinct features within the Plainview occupation area. Scattered burned rock and a few fragments of deer and bison sized animal bone were found. One area of charcoal was clearly intrusive (a rodent burrow?) from the deposits above.

At the time the St. Mary's Hall Site was excavated in 1977, it was the only documented Plainview campsite in Texas. It is fairly small in area and limited in the range of artifacts recovered. Perhaps it represents a hunters' encampment overlooking the Salado Creek valley to the east. No direct radiocarbon dates were obtained from the Plainview component. Comparisons with similar materials from Bonfire Shelter (Val Verde County) and the Lubbock Lake Site (Lubbock County) suggest that this early occupation is 8200 -8000 B.C. The archeological collections from St. Mary's Hall, along with site records, photographs, and other documentation, are on file at the Center for Archaeological Research, University of Texas at Austin. A set of casts of many of the Plainview and other early artifacts is on file at the Texas Archeological Research Laboratory, University of Texas at Austin.

Thomas R. Hester, Early Human Occupations in South Central and Southwestern Texas: Preliminary Papers on the Baker Cave and St. Mary's Hall Sites (Center for Archaeological Research, University of Texas at San Antonio, 1978).

The following, adapted from the Chicago Manual of Style, 15th edition, is the preferred citation for this entry.

Thomas R. Hester, “St. Mary's Hall Site,” Handbook of Texas Online, accessed August 18, 2022,

Published by the Texas State Historical Association.

December 1, 1995