My husband and I had visited the Badlands in 1990, before the Park Service added a gate and the visitors' center and the overlooks. We found that part of the park much changed. The rest, however, looked familiar, though on this trip I photographed it with a digital camera.
The Badlands reveal its layers of rock very precisely.
The Yellow Mounds are a layer of sandstone laid down 55 million years ago on top of Pierre Shale, the base rock in the Badlands.
Several years above the Yellow Mounds are successive layers of the White River Group, ranging from grey clay, to white sandstone to the red and brown sandstone in the Brule Formation, laid down 32 million years ago.
Two formations-the Rockyford,volcanic ash and the Sharps, sandy siltstone- form the Windows and Doors, a formation that is irresistible to hikers who must look through the door or hike to the very top.