Pierre Shale

Pierre Shale 73 –70 million years ago: The Visitor and Nature Center, and most of Colorado Springs are built on top of the Pierre Shale formation. The Pierre Shale formed when Colorado was under a deep ocean. Sea sediments, mostly mud and clays, formed this layer, which is around 5,000 feet thick. Fossils, such as ammonites and mosasaurs have been found throughout the Pierre shale.

A rock marker labeled "Pierre Shale" with age details, surrounded by grass and trees.
Cross-section diagram of Colorado Springs geology, highlighting Pierre Shale layer.
Aerial view of a landscape with numbered paths and rocky formations.