Why are they called Badlands? Various sources including the National Park Service (South Dakota) report that this is a direct translation from the Lakota words of the Sioux people. The area was so called because it was dry, rugged and subject to extreme temperatures.
Today the word badlands has a geological meaning. In Alberta, the Badlands (also called Hoodoos) are located near Drumheller, as well as around Medicine Hat and Writing on Stone on the Milk River. They form when dry climates erode sedimentary rocks.