Colorful Rock
South Dakota
Colorful, rounded mound formations with more angular, striated formations in the distance, near Dillon Pass. The formations in Badlands contain sandstones, siltstones, mudstones, claystones, limestones, volcanic ash, and shale. These rock types come from a number of different sources. For example, many of the sandstones found in Badlands are the remnants of ancient river channels. The occasional limestone lenses found in the park come from calcium-rich groundwater flowing through ancient lakes and precipitating out calcium carbonate, otherwise known as limestone. Photo © copyright by Robert Faucher.