Seven species of reptiles were confirmed during a 2002 park inventory, representing most of the expected species of the area. The racer (Coluber constrictor) was the most widely distributed reptile that was found across all the park sites that were sampled. The western terrestrial garter snake (Thamnophis elegans) is also abundant. The western fence lizard (Sceloporus occidentalis) can commonly be found among the rocks and in trees found along the Snake River.
The ringneck snake (Diadophis punctatus) is a critically imperiled species of concern for the state of Idaho, and the Bureau of Land Management lists it as a sensitive species. Sensitive species are defined as those plant and animal species identified for which population viability is a concern as evidenced by: (a) significant occurrence or predicted downward trends in population numbers or density, and/or (b) significant current or predicted downward trends in habitat capability that would reduce a species' existing distribution. Two juvenile snakes were found at the same location at White Bird Battlefield (Idaho) during the summer of 2002. Dug Bar (Washington) had the highest overall abundance of reptiles throughout the 2002 study.