Archeological Testing of Sites 41WB437 and 41WB438 Webb County, Texas

Abstract

Archeological sites 41WB437 and 41WB438 are two prehistoric sites situated on opposing terraces of San Idelfonso Creek at the crossing of U.S. Highway 83, approximately 7.5 km south of Laredo, Texas, and 0.6 km upstream from the confluence of the stream and the Rio Grande River. Site 41 WB438 is characterized by a relatively dense accumulation of lithic debris and occasional groundstone fragments scattered across a broad alluvial terrace on the south side of the stream. Site 41WB437 is characterized by a much sparser scatter of cultural material on the north terrace. Both sites, but in particular 41WB438, have been heavily modified at the surface by historic activity. Archeological significance testing of the portion of these two sites in the R-O-W of US Highway 83 was conducted by TxDOT personnel in late March and early April, 1997, using a combination of mechanically-excavated and hand-excavated units. The results of testing indicate that site 41WB437 is underlain by thick, silty late Holocene alluvial unit that contains a number of ephemeral, relatively high integrity cultural strata to depths of at least 2 m below the ground surface. While the cultural material associated with these occupations is not particularly abundant, the presence of preserved burned rock features with associated charcoal, bone, shell, and lithic debris suggests that the site has the potential to yield important subsistence and technological information relevant to discrete, short term episodes of cultural activity. Therefore, the site is considered eligible for nomination to the National Register of Historic Places and for designation as a Texas State Archeological Landmark. Because avoidance is impractical, a mechanically-assisted block excavation focused on exposure and documentation of one or more broad occupation surfaces in the upper 1.5 m of the deposit is recommended to mitigate impacts to the site. Site 41WB438, in contrast, consists of a thin veneer of the same late Holocene alluvial fill resting on a much older, culturally sterile alluvial fill. Cultural material is lightly dispersed through the upper 50 cm of the terrace fill, but appears to be in poor stratigraphic context. However, it is possible that intact deposits are preserved in the unexamined portion of the site, which lies to the west of the R-O-W. Therefore, while the site cannot be ruled ineligible, no significant impact to the site's data potential will occur as a result of planned construction activities, and no further archeological work is recommended within the R-O-W.