In 1905, the Union Sand and Material Company of St. Louis operated a lime plant here, where three quarries exist within the park, including the largest one at this location, a smaller one at the base of the bluff, and a third along the Limestone Hill Trail. The rock face is not a natural bluff face; the edge of the original land surface stands at the top of the quarry face, while the working surface is about 35 feet below. Kimmswick Limestone, a crystalline grey limestone approximately 400 million years old, is used in making cement and building stone. Evidence of former quarry operations remains visible on the bone bed below, where brick fragments, concrete slabs, and building remnants scatter along the short trail, and the trail leading up from the bone bed follows the old roadbed to the four-story high quarry. Vegetation in the area today has grown up in the last 75 years after being clear cut during the quarry operations.