The ecosystem of the prairie grasslands, including buffalo wallows and playas are far more complex than explorers, who once called the area the Great American desert, thought. They are crucial to the health and well-being of humans as well as animals, reptiles and plants.A common behavior of the American bison, dust-bathing or wallowing results in a circular soil depression that still persist today, apparently caused by intensive soil compaction over many years, including in Barton County, although according to a study by University of Notre Dame, not all depressions were caused by bison.Clay forms an impermeable floor in a buffalo wallow. The wallows fill with water during wet years and range in size from one to ten meters in diameter.