Year after year, plants like willow and dogwood try to cover the banks of the White River, and year after year they are sheared off by ice. It’s like growing your hear all year long, and shaving it to the scalp each spring. Even the mudbank itself has been cleanly edged — like a potter working heavy clay with a carving-bow. If you look closely, you’ll also see orphaned chunks of ice left high and dry all along the river, and scattered throughout the floodplain fields. Also notice those steeply eroded (dark gray) banks of Pierre Shale? Technically (based on my reading of Philip Stoffer’s work on Badlands geology), what is exposed here is the uppermost layer of Pierre Shale, known as Elk Butte Member. Marine sediments from the Late Cretaceous (imagine a great inland sea covering the land.) The White River, tends to wind from side to side within the floodplain, exposing a sheer flank of Pierre Shale first on one side, then on the other.