375 million years ago, before dinosaurs and when the Catskill region was under a shallow sea, a half-mile-wide meteor crashed here, creating the oldest known meteor impact crater on Earth. The crash was the equivalent of several hundred million tons of TNT and pulverized the bedrock, leaving a 6-mile-wide crater. Over millions of years, different layers of sediment were deposited on top of one another, and with erosion caused by rainfall and the Ice Age, Panther Mountain as we now see it was gradually formed.
On a topographical map, Panther appears to be a nearly perfectly circular mountain, surrounded by two rivers, one flowing north and the other south. The crater is approximately 1.5 to 2 miles beneath the surface of the earth, and due to lack of solid bedrock, the gravitational field here is 0.2% less than in the surrounding areas.
The local Native American peoples, including the Esopus and Mahicans, regarded this valley and region, with its enormous first-growth hemlock trees, as especially sacred, a place of the spirits. They never settled here and only used the valley for ceremonial purposes.