As part of our trip through eastern Wyoming and western South Dakota we spent a night in Hot Springs, SD. When I looked up things to do in the area, one of the top rated activities was called The Mammoth Site. When I mentioned it to our AirBnB hosts, they also said it was worth a visit so we decided to check it out.

This ended up being one of our favorite stops of the trip for a couple reasons:

• The Mammoth Site is home to the largest concentration of Columbian mammoths in the world (58 and counting!). I had never even heard of a Columbian mammoth before our visit, but they were significantly bigger than woolly mammoths (13 feet compared to 9 feet).
• This ancient sinkhole is now an active paleontological dig site with Ice Age exhibits. So part museum, part immersive learning experience, which was very interesting.

The site was discovered in 1974 while the landowner – Phil Anderson – was having the space excavated for a planned housing development. When they unearthed gigantic bones and ivory, they paused their work and reached out to several colleges asking if they could verify their findings. I was shocked to learn that all four places they originally contacted turned them down!

They finally connected with geologist Dr. Larry Agenbroad at Chadron State College in Nebraska, who had his team take a look at the bones. They confirmed they were from Columbian and woolly mammoths, and after a significant fossil discovery in 1975 they decided to leave the bones in their original place of discovery and in the early 1980s they create a building around their active dig site.

It’s pretty incredible to me that the landowner was willing to forgo his original venture and turn this area over to the research scientists who continue their work here today. Through his generosity, The Mammoth Site became a non-profit (501c3) and is now designated a national natural landmark by the National Park Service.

We started our visit with a movie about how the site came to be, how it was discovered, and the research being conducted today. We scanned the QR codes at various places around the dig site to listen to the audio-guide tour, and supplemented with the written information displays and brochure.

There were several researchers down in the site actively clearing away dirt around the bones. It was very cool to watch that happening and see just how big the bones were in comparison to the humans next to them.

The reason there are so many mammoths in this one location is because it’s an ancient sinkhole.

More than 140,000 years ago the mammoths – almost all males – would come down to the water to drink. They would lose their footing on the slippery shale slopes, fall into the water, and then struggle to regain their footing on the steep pond edge. Eventually they would drown in the 25-foot pool of warm water.

In addition to walking around the outside of the site, there were walkways into the site and onto different viewing platforms so you could get closer views of the partially uncovered bones. We got pretty good at identifying the teeth and pelvis, which are featured in the first two pictures below.

While the main focus of The Mammoth Site is mammoths, the museum also has exhibits and skeletons of other animals that met their demise in and around the sinkhole.

So far they have uncovered 85 different species, including coyotes, pronghorn, and extinct species of camel, llama, and short-faced bear. The skeletal structure of the bear was terrifying – standing on all four legs they were 5 foot 10 inches, and standing on their hind legs their claws could have reached as high as 15 feet!

They believe most of the non-mammoth species died around the sinkhole and were swept in by the waves since smaller animals should have been able to scale the shale and get back out.

There is a lot more I can say about what we saw and learned but instead I’m going to encourage you to go and experience this site for yourself! We saw people of all ages enjoying the hands-on activities, reading and listening to the materials, watching the videos and researchers, and learning about the year-round ways to stay connected to their work.

So glad we discovered this incredible site!