The tri-colored bat (Perimyotis subflavus) occurs throughout the eastern United States, from Canada to south Florida and westward to eastern New Mexico, central Colorado, and western Texas. In this study, we document the first record of P. subflavus for both Guadalupe Mountains National Park and Culberson County, Texas. Our record extends the range of P. subflavus into the Trans-Pecos region of Texas. We also examined the diet of this individual and observed that it consisted of Lepidoptera, Coleoptera, and Hemiptera. Our observations of the diet of P. subflavus correspond with results of previous studies from more eastern portions of the species' range.