After being educated in the geology of the Badlands, the traveler is tasked with something peculiar: to make what one sees match what one knows. The various sedimentary layers are color coded for when they were formed. White indicates about 30 million years ago; red indicates about 32 million years ago; grey and yellow about 35; black about 72.
If reconciling such time in a single glance weren’t hard enough, then you find out that we’ve found fossils from alligators and three-toed horses in these fossilized soils. The horse didn’t have a hoof then because three toes did a better job in its environment, which was lush and muddy, i.e., a subtropical rainforest!