The Badlands | Rocks at the Badlands The Badlands’ rock formations are distinguished by their vibrant red, tan, and white stripes. Each stripe represents a different layer of sediment brought there by rivers and seas, millions of years ago. Over time, the mud and grit hardened into layered sedimentary rock. After sedimentary rock formed, the White, Bad, and Cheyenne rivers carved the flat floodplain into sloping hills, jagged cliff faces, and precarious spires. For the whole story with all images, see The Badlands.
