Saguaro National Park (east) is located on the eastern side of Tucson, Arizona. It encompasses both the Tanque Verde Ridge and most of the Rincon Mountains. The park affords a wonderful opportunity to examine a relatively untouched desert environment dominated by Saguaro cactus. We examined the western portion of the Park (defined by the area along Loop Drive) to better understand rocks defined as mylonites, ultramylonites, and cataclasites. In Arizona, these metamorphic rocks are found in the Basin and Range province and are associated with metamorphic core complex mountains. The Saguaro National Park (east) provides an excellent setting to examine these unique shear-altered rocks and understand the processes involved in their formation. Our preliminary assessment indicates that tectonic processes formed these rocks during the Genesis Flood.