Geological History of Badlands National Park

Badlands National Park has been a long time in the making, a very long time actually, the black rock – or Pierre Shale to give it its geological name – is 65 million years old. It’s the oldest formation in the Badlands and was originally formed along the bottom of ancient seas. Above this ancient layer is where the fossils can be found, the Eocene and Oligocene epochs holding countless clues to what types of animals lived and died in the Badlands, long before they were even bad! The remains of many animals were left intact and preserved as fossils after being buried in floods from time to time. This is actually one of the richest fossil beds around, well, that we know of anyway, there’s a great variety of fossils in the Badlands National Park.

So what about the steep canyons, the sharp ridges, the spires, the gullies, the knobs, how did they come to be? That’s all thanks to the Dakota wind, rain and frost – erosion not only created this dramatic landscape but also uncovered many of the Eocene and Oligocene rocks giving us a revealing insight to the past. The Badlands National Park has a real story to tell, you’ve just gotta’ know how to read the signs (I mean rocks).

As the Eocene period was coming to an end, around 34 million years ago, the Badlands was a marshy plain bed by streams from the highlands to the west of the area. Later, when the Oligocene era was coming to and end volcanoes in the west and south west erupted sending gigantic volumes of ash up and onwards into the atmosphere. The wind carried the ash towards the Badlands which fell to form a whitish layer close to the top of the formations. The climate changed slowly but surely, dry winds blowing in from the north and diminishing amounts of rainfall gave the grass the opportunity to take over areas which were previously swamp and forest. This change of habitat meant a change in the animals which made the Badlands their home, more grass eaters moved in and other animals began to disappear.

I agree, the Badlands is a good place – well said!

What a great video. Very informative, very clear, very interesting, just great . . .