Pinnacles Overlook

View of the highlands of the Pinnacles Badlands. The cliffs and buttes at the top of the canyon are the Sharps formation, whereas the lower cliff slopes are the Brule Formation. Some of the narrow ridges in the Pinnacles area follow resistant rock of clastic dikes. The clastic dikes formed as vertical fractures (possibly deep dessication fissures) filled with sediment. The fractures formed as the White River Beds dried out over time. The fractures are also possibly related to the tectonic activity related to the Sage Creek Anticline that partly underlies the High Pinnacles area.