An in situ display of fossil mammoth bones is the centerpiece of The Mammoth Site, Hot Springs, South Dakota. (photo courtesy of Pati Blackwell) click to view slideshow...
The Mammoth Site of Hot Springs (South Dakota)
About 26,000 years ago, a sinkhole opened up in what is now South Dakota, and began to fill with warm water from an underground aquifer, turning into a lush oasis that attracted herds of mammoth roaming the North American plains. When the animals entered the pond to drink or feed, they became trapped by the slick, steep-sided walls of the sinkhole. Sixty individuals died here, either from exhaustion or starvation during their attempts to escape. As a result, the Mammoth Site at Hot Springs, South Dakota, is now one of the most interesting and diverse paleontological sites in the United States.
While the majority of the mammoths found at the site were Columbian mammoths (Mammuthus columbi), the remains of three wooly mammoths (Mammuthus primigenius) were also found. Typically, Columbian mammoths are associated with grassland habitats, where wooly mammoths are associated with tundra/alpine environments. Finding the two species at the same site suggests that at one point, the climate was cold enough to push Columbian mammoth south and let wooly mammoth roam the area briefly. Other Pleistocene animals found at Hot Springs include camel, llama, short-faced bear, and grey wolf, likely drawn to the water the way the mammoths were.
The site was first discovered in 1974 during when a bulldozer operator uncovered enormous bones excavations for a housing development. When scientists and the community realized the extent of the deposit, the developer sold the land at cost to The Mammoth Foundation, a nonprofit organization dedicated to helping preserve and manage the Hot Springs Mammoth Site. The decision was made to leave the bones in situ because of how concentrated the deposit was. The bones themselves are very fragile. Unlike most fossils, the bones at Hot Springs have not been permineralized, having instead been leeched of collagen by the very waters that formed the sinkhole in the first place, and then dried in the surrounding sediment.
Currently, the Mammoth Site is engaged in active research into many different aspects of mammoth paleontology. One recent visiting scientist examined the plaque on mammoth teeth to determine diet, and members of Earthwatch along with students from the surrounding community have recently uncovered the 120th tusk in the sinkhole.