Badlands

Warm climate and abundant rainfill produced lush vegetation. Here strange animals lived, died, and sank into the swamps to become buried by accumulating sediments.

After hundreds of centuries of erosion, rejuvenated rivers washed much of this material away forming huge valleys and deep canyons. Winds and rain continue to cut into this great plain, exposing the most outstanding examples of Oligocene deposts and fossils known and form these roughly hewn pinnacles, buttes and spires.

Muddy mountain streams dropped their loads of soil and gravel in the South Dakota Badlands to form a huge flood plain during the Oligocene Epoch 35 million years ago.