A gigantic map of all the cool plaques in the world. A project of 99% Invisible.

Quarry Operations

 The rock face before you is not the natural bluff face. In 1905, the Union Sand and Material Company of St. Louis operated a lime plant here. Three quarries exist within the park; you are standing in the largest one. A smaller one exists at the base of the bluff, and the third resides along the Limestone Hill Trail.
At the top of the quarry face is the edge of the original land surface. You are standing on a working surface about 35 feet below. Kimmswick Limestone is approximately 400 million old. The rock, a crystalline grey limestone, is used in making cement and building stone.
Evidence of the former quarry operations is visible on the bone bed below. Brick fragments, concrete slabs, and building remnants scatter along the short trail. The trail leading up from the bone bed is 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.

Nearby Plaques On Google Maps