Rattler Gulch Limestone Cliffs ACEC

Rattler Gulch Limestone Cliffs ACEC. (Area of Critical Environmental Concern). The limestone feature (outcrop), located across the road, known as the Madison Limestone Formation, was deposited about 350 million years ago in a shallow sea. It was uplifted about 65 million years ago during the Laramide Orogeny (when the Rocky Mountains were formed.) During its uplift the cliffs were folded and faulted, adding to the geologic structure of the cliffs. , Approximately 1635 feet of the Madison Formation are exposed in this location. It is partly composed of the fossil remains of small marine animals. Erosional processes of the bedding planes in the formation reveal ancient sea floors. , The ACEC designation means that BLM is giving these limestone cliffs special emphasis and protection. This outcropping of the Madison Formation is unique in its entire exposure. The site is used by universities and high schools for geologic study and investigations, as well as being available for public viewing and enjoyment.