The peaks, buttes, and wide prairies of the Badlands can be challenging to cross, yet they have long attracted the interest and praise of travelers. Frank Lloyd Wright in 1935 stated: "I've been about the world a lot, and pretty much over our own country, but I was totally unprepared for that revelation called the Dakota Bad Lands ... What I saw gave me an indescribable sense of mysterious elsewhere - a distance architecture, ethereal ... an endless supernatural world more spiritual than earth but created out of it."
The Badlands Wall constantly retreats north as it erodes and washes into the White River Valley. The Wall, an intricately carved cliff, divides the upper from the lower prairie. The Wall is more than 60 miles long. It is the geologic feature around which park boundaries were drawn. The road through the park is called the Loop Road, follows the wall. Anywhere a wagon could be worked up and down the Wall was called a pass by homesteaders. Getting a team and wagon through one of the steep, uneven passes was not to be undertaken lightly.
Water is scarce in the Badlands, which get less than 16" of precipitation per year. The bowl-like Cliff Shelf shelf here provides more moisture than commonly found in this desolate land. Drawn to this spot for more than 11,000 years, humans have used the area for everything from ancient hunting camps to modern lodges.
Jungle on a seabed ~~ The sea's signature is ammonites, baculites, and clams, pearly fossils entombed in a fossil mud called the Pierre Shale. This shale is exposed in the gullies seen in the Badlands. A jungle sprang up after the sea drained away about 65 million years ago. For a long time tree roots broke up the shale, and chemicals from decaying plants produced a yellow soil. About 37 million years ago sediment from the west washed over the jungle. The jungle rebounded, converting the new sediment into a red soil. Buried by later sediments, both yellow and red soils were fossilized. We call them the Yellow Mounds Paleosol and the Interior Paleosol.
Color layers exposed in the slopes mark fossil soils which were formed during the Oligocene and Eocene Epochs. They contain evidence of life here between 37 and 23 million years ago.
Thirty-five million years ago there was a warm climate with ample rain produced open woodland. The saber-toothed cat prowled the woods along with the nearly elephant size mammal of the Eocene. Thirty million years ago during the Oligocene the climate became drier and cooler, restricting the woodland to stream banks. Low plants grew among scattered trees. Here a tiny deer-like animal and numerous land snails and land tortoises.
By twenty-three million years ago the climate was even cooler and drier, and trees were absent except near streams. Low shrubs, wild flowers, and grass formed the first North American prairie. Burrowing beavers lived there, much in the style of today's prairie dogs. At the bases of some of the buttes you can see a yellow fossil soil beneath a red fossil soil.
Thirty-seven million years ago the ancient crystalline core of the Black Hills had already been exposed by erosion. The long blue profile of those mountains, visible to the west, looked much as it does now. About that time, streams flowing from the west began to deposit sediments in this area. Most of the sediment was wind-blown volcanic ash that had settled into the watershed which fed the streams. Occasionally the rivers brought gravel and stream-worn rocks from the Black Hills themselves. The ash weathered into clay, and turned into rock. Erosion did not begin to gully the Badlands layers and foretell the present landscape until quite recently, perhaps only half a million years ago.
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