Today the Badlands of South Dakota are a place of extremes. The summers can be extremely hot with daily thunderstorms and the winters cold with winds unhindered out of the north. It is a place of beauty with colors of the sky and the earth.
Approximately 75 million years ago the Earth's climate was warmer than it is now. A shallow sea teeming covered the region. Many fossils can be found in the area from this period. Eventually the pushing and shoving of the continental plates caused the ancestral Rocky Mountains to rise out of the sea. The area of the Badlands eventually drained and was exposed to air and sunshine.
The climate was humid and warm with abundant rainfall. A subtropical forest developed. In time the climate became cooler and drier giving way to savanna, then to grasslands much as is present today. Over time erosion produced the area as it is today.