The Mammoth Site

In 1974 a construction worker, George Hanson, unearthed unusual bones while working at a construction site near Hot Springs, SD. The construction site turned out to be sitting on a prehistoric sinkhole filled with pleistocene fossils, primarily mammoths. The owner of the construction site donated it to the Mammoth Site of Hot Springs South Dakota, Inc. This non-profit organization administers the museum and dig site, and oversees paleontological excavations , research, and education. I toured the Mammoth Site in July 2025.

The Mammoth Site

Mammoth Sign

There are signs along the sidewalk from the parking lot to the museum describing the various time periods in Earth's history. The earliest time is near the parking lot. This is the Precambrian Era, 4.25 billion to 540 million years ago. Once you get to the building you've traveled in time all the way up to the Pleistocene Epoch of the Cenozoic Era, some 2.5 million years ago.

Precambrian Era

Paleozoic Era

Paleozoic-Mesozoic Era

Late Mesozoic Era

Mid-Cenozoic Era

Museum Entrance

Lobby and Gift Shop

The first thing to do is watch a short film that will introduce the viewer to the world of mammoths. Then it's off to the main hall.

Lobby Mammoth

Pleistocene Mural

Mammoth Anatomy

Well stocked gift store

Mammoth Mugs

Main Hall and Sinkhole

The main hall of the museum encloses a prehistoric sinkhole, 120 by 150 ft wide and 65 feet deep. The sinkhole gradually filled with silt over hundreds of years. The fossil remains of 61 mammoths along with other pleistocene animals have been found so far, and paleontological excavation is ongoing. I walked clockwise around the sinkhole while taking these photos. The last couple are in the deep end of the sinkhole. The museum has an app using QR codes that explains the numbered stops around the sinkhole, which of course I didn't use.

Mammoth Tusks

Bunch of Bones

Mammoth Molars

Giant Short-Faced Bear (Arctodus simus)

Mammals of the Pleistocene

Mammoth Relatives

A Mammoth Fall

Haven't a clue about #11

Columbian Mammoth (left) Woolly Mammoth (right)

Bones in the deep end of the sinkhole

Intact Tusks and Skull

Fairly Intact Mammoth Skeleton

Other Exhibits

Galleries off the main hall contain additional exhibits and interactive displays. Included are more pleistocene fossils and paleoindian displays. There is also a Kids Cave and lots of activities for all the junior paleontologists.

Dire Wolf (Canis dirus)

Harlan's Ground Sloth (Paramylodon harlani)

"Saber-tooth" cat (Smilodon fatalis)

Mammoth Femur

Bone Flake Tools

Paleoindian Arrow Points

This concludes our tour of the Mammoth Site Museum. Hope you enjoyed it and learned a little about mammoths. I did.