Forming a Cave:
The cave’s story began 320 million years ago, when southcentral
Kentucky was covered by a shallow, warm tropical sea. Hard parts
of ocean animals – shells and coral – broke down into sand and
accumulated on the sea floor. These eventually compacted into
solid layers of limestone bedrock, perfect for forming caves.
Other ideal conditions for caves were here – abundant rainfall, warm
temperatures, and lush vegetation. These provided carbon dioxide,
which acted as an acid to dissolve rock. Rainfall also created sinkholes
and underground streams, which dissolved the cave walls as they
flowed to what is now the Green River.