These are some pictures from our trip into Badlands National Park.  For the most part these lands are truely empty.  There is less than 16 inches of rainfall a year, so a grass prairie is the dominant feature.  The land is fertile.  Over millions of years, several inland seas covered the area alternating with jungle and forests.  Lots of fossils are found buried here both dinosaurs and more recent Mammoths, Saber-toothed cats, Giant short-faced bears and many others.  The land is still set in the layers it was formed in.  Erosion began, and the harder places remain as pinnicles and mounds. 
In these  pictures you can see the erosion proccess at work, tearing down the mountains, into mounds, into grassland.  As soon as the land becomes flat enough to hold seed, it sprouts grasses.  The layers of soil are very evident.  The yellow layer is from a period when a dense jungle covered the land. 
Fossil of a long extinct species!