Archaeological Investigations of the Theo Avenue Realignment, Mission Concepción Portal and Concepción Park, San Antonio, Bexar County, Texas

Between May and July of 2010, the Center for Archaeological Research (CAR) at the University of Texas at San Antonio (UTSA) conducted an archaeological survey of the area to be impacted by the proposed realignment of Theo Avenue, the construction of the Misssion Concepción Portal, and the improvements at Concepción Park. The goal of the project was to determine if the proposed improvements would affect any significant cultural deposits. The focus of the investigations was threefold: 1) locate evidence of the Battle of Concepción; 2) discover any prehistoric sites that may have existed on the banks of the old meander of the San Antonio River found within the Area of Potential Effect (APE); and 3) re-discover any irrigation features that would be impacted by the proposed realignment. Investigations were conducted under Texas Antiquities Permit No. 5627 and Dr. Steve A. Tomka, Center Director, served as the Principal Investigator. The investigations carried out by CAR included archival research, compilation of oral history, and field investigations consisting of shovel testing, extensive backhoe trenching, limited metal detecting and Ground Penetrating Radar (GPR) survey. During the field investigations, 115 shovel tests were excavated within the APE. Thirty-five backhoe trenches were excavated to investigate the potential for deeply buried deposits and to search for irrigation-related features. Shovel testing did not produce significant prehistoric cultural deposits, nor evidence of the Battle of Concepción. However, it was able to document extensive disturbances across the APE. Backhoe trenching revealed a portion of a secondary lateral to the Main Ditch employed by St. Peter’s and St. Joseph’s Children’s Home (St. PJ’s) during the early 1900s to irrigate their agricultural fields. We assume that the junction of this secondary lateral with the Main Ditch is nearby and may be within the proposed Theo Avenue Right-of-Way. Both features are associated with agricultural activities carried out at the orphanage and do not date to the Spanish Colonial Period. The bulk of the Spanish Colonial Concepción Acequia desague (discharge channel) appears to be located under the present route of Theo Avenue. The small segment that may be south of the road will not be directly impacted by the proposed construction. In addition, backhoe trenching within Concepción Park discovered portions of a stone wall lining the bank of the old San Antonio River. We believe that the wall was constructed during the Civilian Conservation Corps (CCC)-era. The feature may be related to the installation of a pump house by St PJ’s Orphanage to access the water of the San Antonio River. The remainder of the wall lines more than 150-feet of the buried bank of the river. The CCC-era stone wall, the lateral of the Main Ditch of used by St. PJ’s as well as the Main Ditch itself will be impacted by the proposed realignment of Theo Avenue. While the early 20th century irrigation features are not as old as the Spanish Colonial Concepción Acequia and desague, they are still vestiges of the continuity in irrigation technology and therefore represent a significant historic resource. All three of these features are found within the proposed Right-of-Way. Therefore, CAR recommends that these features be highlighted through interpretive signage, and we also recommend the exposure of some of these features where feasible and without harm to them and their integration into the planned improvements to Concepción Park. The integration of these significant historical features into the modernization of the park will serve as an important link of the land, its features and its people to the history of the neighborhood and park. In addition, the CAR recommends that selective construction monitoring take place in portions of the project area that will undergo significant grade changes or of activities that will result in deep impacts (i.e., drilling for light pole installations, tree plantings) that could not be investigated to date. All artifacts and project associated records are permanently housed at the curation facility of the Center for Archaeological Research at UTSA.