| The Sharps Formation is youngest sedimentary rock formation of the White River Group. The Miocene sediments of the Sharps Formation crop out near the Pinnacles Overlook. This view is looking north toward the upland prairie near south end of the Wall Escarpment. The Wall Escarpment is a belt of White River Badlands that extends from the Pinnacles area northward toward the town of Wall, South Dakota. The Wall Escarpment represented a barrier to early travelers heading west toward the Black Hills and Wyoming Territory (The town of Wall, South Dakota developed at the north end of the Wall Escarpment). The trail up the small hill behind the Pinnacles Overlook sign leads to the top of a small knob of the Sharps Formation. |
