Just south of Wind Cave, is a on-going archeological dig of a site that contains as many as 50 almost complete mammoth fossils. It is the site of an ancient sink-hole that was fed by a hot spring. Because the water was warm, the mammoth would come to drink the water or feed on the grass surrounding the hole. But due to the unstable ground around the hole, they would often fall in and not be able to get back out. Most are fossils of Colombian mammoths which were much bigger than Wooly mammoth. There are also fossils of short-nosed bears which are almost twice the size of grizzly bears.