The Badlands: Seventy-Five Million Years Exposed

Drive the Loop Road in the morning and the formations will be pink before they turn gray, the shadows lying long in the gullies between the spires. What you are looking at is a cross-section of time. Each band of color is a different era: marine sediment from an inland sea, subtropical forest soil, volcanic ash falls from eruptions to the west, ancient grassland compacted into clay. The whole sequence reads like a geological textbook printed in stone, and erosion writes a new page every spring.

The exposed rock here is primarily from the Oligocene epoch, roughly thirty-three to twenty-three million years ago. Fossils of titanotheres, prehistoric relatives of the rhino as large as modern elephants, erode out of the White River beds after heavy rain. Three-toed horses the size of dogs. Predatory entelodonts with jaws like a bear. Paleontologists have been collecting here since the eighteen forties, and the park's fossil record is still actively yielding new material.

The Lakota word for this terrain is Mako Sica: bad lands. The name was practical. The eroded maze of ravines and pinnacles was genuinely impassable for horses and on foot, a landscape that blocked movement rather than permitted it. French Canadian trappers in the early nineteenth century translated it as 'bad lands to travel through.' The phrase stuck.

The park's North Unit, the part you can drive in an hour, is managed by the National Park Service. The South Unit, called the Stronghold District, is co-managed with the Oglala Sioux Tribe and is where the Lakota took refuge during the Ghost Dance winter of eighteen ninety. That is a different story, told at a different stop.

Here, the story is in the stone: seventy-five million years of it, cut open and left in the wind.