Article Title

Archaeological Testing of Site 41BX6, The Alamo, City of San Antonio, Bexar County, Texas

Authors

Nesta J. Anderson
Kristi Miller Nichols
Steve Tomka
Clinton McKenzie
Alamea N. Young
Melanie Nichols
Mary Jo Galindo
P. Shawn Marceaux
Jose Zapata
Jason Perez
Sarah Wigley

Agency

Texas Historical Commission

Abstract

In support of the Alamo Master Plan, Preservation Design Partnership (PDP) of Philadelphia, Pennsylvania, hired Pape-Dawson Engineers along with subconsultants Raba-Kistner Environmental Consultants (RKEI) and the Center for Archaeological Research at the University of Texas-San Antonio (CAR) to lead an archaeological effort at the west and south walls of the Alamo (41BX6). This effort was designed to build upon previous work at the Alamo in order to answer several research questions the Master Plan team has about the compound boundaries and previous living surfaces. These questions, included in the research design for the Texas Antiquities Permit application, have been refined over time so that they are:

1. Can the outer limits or edges of the Alamo “walled compound” be located and delineated through existing data from past archaeological campaigns and/or supplemental and targeted archaeology to be undertaken as part of the Master Plan?

2. Can archaeology help delineate the landscape features of the mission compound, such as acequias, plant material, etc.?

3. Given the layers of late-nineteenth and twentieth century disturbances and construction, can the 1724 and 1836 elevations be determined?

4. Can the relationship between the river and the 1724 and/or 1836 living surfaces be determined along with the topography of the site, particularly along the southwest corner of the mission compound, where the shortest distance to the river appears to exist?

As the excavations took place primarily on land owned by the City of San Antonio (COSA), compliance with the Antiquities Code of Texas was required, and Texas Antiquities Permit #7692 was obtained prior to field investigations. In addition, the project area falls within the San Antonio City Limits and partly within COSA’s River Improvement Overlay (RIO) District 3, necessitating compliance with COSA’s Unified Development Code (UDC). In compliance with these regulations, the archaeological team consulted closely with the Texas Historical Commission and the COSA archaeologist.

The current investigations focused on a ground penetrating radar (GPR) survey to supplement existing GPR data and revisits to both 41BX6 (a State Antiquities Landmark) and 41BX438 (recommended for State Antiquities Landmark status according to the site form) to perform further archaeological testing in these areas. While these two areas have been given separate site numbers previously, agency consultation agreed that the current effort would be for site 41BX6, especially since one of the research goals was to confirm the boundaries of the Alamo compound. The GPR results are presented in a separate technical report.

Previous investigations indicate remnants of the south wall and lunette are present at 41BX6, and suggest that the Spanish Colonial living surface was not present in these areas. At 41BX438, previous investigations revealed adobe brick piers, adobe brick walls, stone walls, and other architectural iii features associated with the west wall complex were present at the time of the 1979 and 1980 excavations, as were Spanish Colonial deposits. The 2016 archaeological testing sought to build upon this previous information to confirm whether these types of architectural features and archaeological deposits continue to exist adjacent to areas that were excavated previously.

An area adjacent to the north side of 41BX438 was designated as Locus A and targeted as part of the current investigations at the west wall. A total of seven 1x1 meter (m) units were excavated in this area, although some units were excavated as a block to provide better horizontal coverage. Within these units, a total of six features were discovered, including an adobe brick pier and a collapsed adobe wall. In order to preserve deposits in place for future interpretation for the Master Plan team, archaeologists halted excavation upon reaching potentially intact deposits in all units with the exception of two areas. One 0.5 m x 0.5 m unit sample within Unit A-2 and one 0.35 m x 0.5 m within Unit 6 were excavated through potentially intact deposits to confirm they were intact. An intact living surface likely dating to the Spanish Colonial period (1724-1792) was discovered in both these sample areas. Evidence of wall collapse was also observed in Units A-2 –A-5. A total of 1,526 artifacts was recovered from Locus A, including Spanish colonial and European ceramics, Native American ceramics, container glass, a brass finial, faunal bone, and lithic debitage.

Archaeologists designated an area adjacent to and extending partly into the east side of Alamo Street as Locus B. This excavation was intended to provide additional information about potential archaeological deposits associated with the south wall of the Alamo. A total of nine 1x1 m units were laid out at this location; of these, eight were excavated. An additional 1 m x 0.3 m unit was excavated adjacent to Unit B-1 to investigate a disturbance. Four features were found in this area of the site, including a wall footing and a utility trench. A shovel test excavated within the utility trench confirmed the presence of curved pipe suggestive of a utility casing approximately 155 cm below the current ground surface. This area yielded a limited number of artifacts, and did not provide conclusive evidence for intact living surfaces being present within the excavation area. A total of 255 artifacts was recovered from this area, including lithic debitage, a few Spanish colonial ceramics, faunal bone, and a sword tip.

Architectural remnants of the wall complexes uncovered during the 2016 excavations at both the west and south walls indicate that additional archaeological data about the compound boundaries is available in some areas that have not been previously excavated. In addition, these excavations were designed to confirm the presence of archaeological deposits and to sample these deposits to see whether they may be intact without destroying them completely, so that additional information potential remains to help answer questions about the previous landscapes at the Alamo. Based on the excavation results, there is an intact Spanish Colonial living surface at Locus A, while at Locus B, no intact living surface was present. These findings are consistent with previous excavation data at these locations.

In accordance with the criteria in 13 TAC 26.10, Pape-Dawson’s testing of site 41BX6 has confirmed that the site contains deposits worthy of SAL designation at both the south and west walls of the Alamo Compound. As excavations were designed to preserve archaeological features and deposits in place rather than to excavate through them, there is additional information potential present not only in iv deposits surrounding the excavated areas, but also still in the excavated units themselves. As a result, the Principal Investigator recommends the site be protected from disturbance until the deposits present in these areas can be publicly interpreted and/or excavated thoroughly at a later date with appropriate research goals and questions. Deposits at both Locus A and Locus B have been covered with landscaping fabric, a layer of clean sand, backdirt, and then construction base and pavers.

A site revisit form was filed with the Texas Archeological Research Laboratory. Project records, photographs, and artifacts will be curated at the Center for Archaeological Research at The University of Texas at San Antonio.

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