Cataract Falls resulted from oceans and ice. The limestone outcroppings that form the falls formed millions of years ago when this region was covered by a large shallow ocean. Layers of calcium-rich materials fell to the ocean floor, and as layers accumulated, their weight pressed down, creating limestone. More recently, glaciers extended south into the Cataract Falls area. Ice blocked the natural drainage of Mill Creek, creating a large lake, and the limestone bedrock became buried under lake sediments. Once the glaciers receded north, the lake drained and Mill Creek carved its path across the dry lake bottom. It cut through the soil deposits until it encountered two limestone ridges, which became the Upper and Lower Cataract Falls. Cataract Falls carries the largest volume of water of any falls in Indiana. The upper falls is 20 feet high, and the lower falls are 18 feet high.