Data recovery excavations at three sites near Amarillo, Texas, have yielded lithic assemblages dominated by Alibates and Tecovas materials. The visual distinction between these two southern Plains chert types partially overlaps in color, banding patterns, texture, and translucency. To help resolve this visual identification problem, samples from five spatially distinct Tecovas outcrops, two spatially distinct Alibates outcrops, and one gravel source were submitted for instrumental neutron activation analysis (INAA) at the University of Missouri Research Reactor (MURR) Archaeometry Laboratory. The INAA results geochemically separate Tecovas and Alibates and further differentiate geochemical signatures of multiple Tecovas source areas. These chemical results can now be used to correctly identify and sort chipped stone tools and debitage from archaeological context beyond the two source areas.