According to the Arizona Department of Transportation, approximately 23,000 vehicles travel through the impressive scenery of the Virgin River Gorge on Interstate 15 daily. Located in the northwestern corner of Arizona, the Virgin River Gorge can be considered with a modest dose of imagination to be a geological example of the rabbit hole in “Alice in Wonderland.” With even a passing interest, it becomes evident that there are major changes in the geography and geology from one end to the other. These changes are due to the fact that hiding in plain sight within the gorge is a major geologic province boundary. This boundary separates the Colorado Plateau Province on the east from the Basin and Range Province on the west (Figure 1). Significant differences geographic and geologic features are a result of differences in the geologic history and the geologic processes that are operating below the surface of these two provinces. Exposed rocks visible in the gorge, however, provide “forensic” evidence for what is happening.