Erosion
The Loess Hills were formed by wind blown silt from the Missouri River floodplain. The silt had originally been deposited by melt waters flowing out of the glaciers in the upper Midwest. Following the wind deposition, the landform experienced periods of erosion that shaped the land we see today. For the last 9,000 years the Loess Hills have been blanketed with a diverse, deep-rooted prairie system that is well suited to hold the highly erodible loess. During the last 150 years, Euro-American settlers and their descendants have imposed changes on the landform that promote accelerated rates of erosion. In fact, today, the Loess Hills experience the highest rates of erosion in North America (30 - 40 tons/acre). Restoring the Loess Hills biological communities and decreasing disturbance to the soil is the key to reducing erosion in the Loess Hills landform. Hitchcock Nature Center protects the hills from soil mining and plowing, and is restoring the prairie, and oak savanna that hold the soil.