The Mammoth Site of Hot Springs is an ancient water hole which also became the resting place of tons of mammoths that got stuck in it in the last Ice Age. The remains have been preserved by the layers of silt and sediments that accumulated in the sinkhole from the end of the Pleistocene era to the present.

Today, the Mammoth Site of Hot Springs in South Dakota serves as the largest Columbian mammoth exhibit and research center in the world. It opened in the late 1970s, after the bones were excavated while the area was being prepared for building a new subdivision. The site was immediately designated as a National Natural Landmark in the year 1980 for the massive amount of mammoth remains that were uncovered.