Over 18,000 years ago, glaciers covered what is now called the bread bowl of America. As the ice age ended and the earth’s surface warmed, the ice started melting, causing a large and wild river of runoff where the present day Missouri River flows. However, because of the summer and winter seasons, the river of runoff would slowed and even disappear yearly. Particles of debris that had been scrapped up by the glaciers lay in the river’s dry channel. Winds from the west picked up the flour-like dust, called loess, and piled it on the eastern bank of the river way. Eventually, the piles turned into dunes, and the dunes turned into hills, pure hills of loess. Three distinct layers of loess run through the Loess Hills from different eras of glacier melting. At the bottom, the Loveland Loess from the Kansan Glacier traps whatever moisture it can, giving it clay-like properties. This dense, reddish soil is considered the most valuable because it remains moist much longer than the other layers in the dry hills. In the middle, the bluish Post-Kansan Loess is fine and dense, much like flour, but it slowly absorbs moisture, like coco powder. Finally, the yellowish Post-Iowan Loess on the top gives the Loess Hills its odd physical characteristics. Instead of gentle slopes where the soil erodes away, the loess slips away in columns, leaving behind steep walls. Where the loess cannot fall away in columns, “cat-steps,” step-like structures, stretch across the hilltops.