Located in the Eastern side of the very long and flat state of South Dakota is the Badlands National Park. The road from the east leading to this park is extremely monotonous and tiresome. The great plains can put the most wide awake person to sleep in a couple of minutes. The flat terrain capped by the cloudless blue skies are like a children’s lullaby. Seventy five million years ago this was not the story. The climate was much warmer and the seas were much higher. The central part of North America was covered in a great shallow sea that we see as the Great Plains. It’s shores reached from the Gulf of Mexico to Canada and from western Iowa to western Wyoming. There was a wealth of life and activity during this period. In the Badlands park this time period can be witnessed in the deep ravines where a dark gray layer of rock can be found located near the bottoms. This sedimentary rock is a shale that is referred to as Pierre. This layer is also enriched with millions of fossils of animals that died, sank to the bottom and were preserved in the shale rock. The minerals in this layer replaced the easily erodible bones to make the hardened fossils. But then the environment started to change. The Rocky mountains began to lift up due plate tectonic movement that had two plates crash into each other. Rain in the mountain range began to erode away the topsoil layers of the mountains. The rivers dumped the sediments to the east, which is where the Badlands National park and Great Plains are located. Sand, silt, and clay, mixed together with volcanic ash and began stacking layers like a seven layer cake until the pile was thousands of feet deep. During this time, there was an abundance of life surrounding the flood plains. There were many mammal species that were preserved in these layers that make the badlands one of the richest areas of mammalian fossils on earth. The layers were capped by a final white ash layer from a volcanic period. My senior year in college, I toured the west with a paleontology class from my school. Our best find was in the badlands. It was a Titanothere skull, which is an ancestor of the rhinoceros except it was much bigger and hairier. The skull was actually not that hard to find because fossils were just sticking out of the ground. Once we found something foreign protruding from the ground, we started digging around it to uncover the treasure. The Titanothere skull was a huge surprise. We spent 3 days digging around the head, wrapping it in plaster, and transporting it back to camp. Most of the Badlands area does not have vehicle access.
After the volcanic ash layer cap was deposited, the land was lifted up. The White River that formed in the Rocky Mountains began to erode scarps through the sedimentary layers of the Badlands. The tributary streams and creeks also began eroding the gullies and spires that make up the incredible landscape of this National Park.