Scientists believe nature began to slowly craft Howe Caverns some six million years ago; long before even the ancient, extinct animal known as the woolly mammoth appeared on Earth. Age and beauty are not the only qualities that make our caverns unique. They also happen to be one of a very small number of mineral caves (living limestone cave) in the world. Long ago, the eastern part of New York State was covered by an arm of the Atlantic Ocean. Corals, sponges and many creatures similar to oysters, clams and snails were abundant in these waters. Many of these creatures built their shells from calcium carbonate, which they gathered from their watery home. As this sea life died, their empty shells and fine particles of dirt covered hundreds of feet of the ocean floor. At first, these deposits were very soft. As layers of new deposits fell to the bottom the pressure built up. The lower layers were pressed into a type of rock called limestone. As millions of years passed, the continent of North America rose slowly out of the ocean. This was during the Cretaceous period of Earth’s early history some 65-136 million years ago.