Archaeological Assessment of Three Locations on the San Antonio River, San Antonio, Bexar County, Texas

In May 2010, staff archaeologists from the Center for Archaeological Research (CAR) of the University of Texas at San Antonio (UTSA) conducted an assessment of three areas along the San Antonio River between Theo Avenue and Mission Road. This work was completed under Antiquities Permit No. 5622 and National Park Service Permit No. SAAN-2010-SCI-0001, under the oversight of the U.S. Army Corps of Engineers, the Texas Historical Commission, and the City of San Antonio. The Principal Investigator was Dr. Steve A. Tomka and the Project Archaeologist was Barbara A. Meissner. The three areas consisted of 1) the possible location of a remnant of the San José Dam, constructed in the mid-eighteenth century; 2) a location near the Poor Family Cemetery (41BX264) where concrete curb-like elements, reminiscent of a kind of grave decoration common in the later nineteenth and early twentieth centuries, had been observed; and 3) a location south of Concepción Park where prehistoric artifacts and a limestone rock alignment had been observed. Three backhoe trenches (BHTs) were excavated into the west bank of the San Antonio River to define the nature of the stone concentrations discovered during grading in the approximate location of the San José Dam. No evidence of a remnant of the San José Dam was encountered. The sediments consisted of fill and riprap placed on the bank during the rechannelization of the river to prevent erosion. Two BHTs were excavated in the vicinity of the fragments of concrete curbing noted on SARA-owned right-of-way. The trenches revealed a stratigraphy dominated by fill from surface to 3.0 m below surface, the terminal depth of the trenches. No evidence was found indicating that the Poor Family Cemetery extended into the SARA right-of-way. Two BHTs were dug in the area where prehistoric surface deposits were noted on the east bank of the San Antonio River, south of Concepción Park. The trenches revealed that the artifacts recovered and burned rock observed on the ground surface have been recently brought in and do not represent an in situ prehistoric site. The limestone rocks noted nearby appear to be part of the layer of rock riprap placed on the slope of the bank to retard erosion during flood events. As no evidence of significant prehistoric and/or historic deposits was found during these investigations, the CAR recommends that the grading along these three locations of the San Antonio River proceed as originally planned. However, due to the possibility that a remnant of the San José Dam is buried under the fill observed during this project, we recommend that an archaeological monitor be present during the remaining grading in the area. In addition, as the exact location of the boundaries of the Poor Family Cemetery is not known, we recommend that an archaeological monitor be present during grading in this area as well. As the prehistoric artifacts constitute a secondary deposit and the limestone rocks on the east bank of the river are riprap, we do not recommend additional archaeological investigations or monitoring on the east bank of the San Antonio River associated with these two deposits.