The raging waters of Rocky River that formed the Berea Falls are a piece of glacial history. Post-glacial river water found its way along the Berea sandstone, seeping through fissures and cracks to the soft shale below. As the shale eroded, the sandstone on top was undermined and began to break off. Those breaks in turn became the Berea Falls. Berea sandstone, named for exposures near the City of Berea, is the remains of ancient river deltas. This highly rated sandstone is world famous. Originally quarried at an early date for grindstones, it was also used in building, both locally and oversees. This rock put Berea, Ohio on the map.