Human-mediated disturbances appear to be ever-increasing and wide-ranging, and if we are to mitigate biodiversity loss, it is essential that we continue to survey and monitor both poorly known and well-understood ecosystems. This recommendation may be especially relevant for Australian herpetofauna, including many snake taxa, as many species are small, morphologically and/or behaviorally cryptic, and occur in specialized ecosystems. Here, we describe a westerly range extension and present the first records of the De Vis’ Banded Snake (Denisonia devisi) in South Australia. We also describe the habitat and our observations of behavior, foraging, and refugia, and discuss potential conservation concerns and recommendations for this newly discovered population. Our discovery contextualizes the need for ongoing fauna surveys, especially near jurisdictional borders. Detection of new populations of fringing taxa will undoubtedly continue to occur across Australia and may have implications for conservation management.