woolly mammoth desperately tries to escape the pit as a fellow
member of his herd looks on helplessly.
(Copyright Lee Krystek, 2000.)
The young bull mammoth looked down into the
tantalizing water. He'd traveled dozens of miles across the
dry plains of this region seeking a place to quench his thirst.
This pool at the bottom of a steep-sided pit looked perfect.
The water was still, and around the edges grew bushes and trees
whose green leaves he could munch on after he drank his fill.
While trying to carefully maneuver down the
slope to a point where he could get his trunk into the water,
the giant's feet slid out from under him on the slippery slope.
He plunged into the water with a tremendous splash. He didn't
panic, though. Mammoths were excellent swimmers and his feet
could touch the bottom of the warm pool even in the deepest
sections. He moved around the edges, drinking and eating from
the bushes until he began to tire. Then he swam to the edge
to climb out.
He had gotten his front feet out of the water
and onto the slippery red walls of the pit when suddenly the
ground there collapsed and he found himself back in the water.
Again he tried to climb out with the same effect. Now tired
and desperate, the animal raced toward the wall again. This
time he got his immense body completely out of the water, but
before he could get a front foot onto level ground, the soil
beneath his right rear foot collapsed. Now the mammoth found
himself tumbling backwards into the water head over tail. The
creature's huge, heavy tusks twisted his head around, breaking
his neck. Slowly the dead giant slid to the bottom of the pit
where loose sand covered his body, another victim of the Mammoth
It was in June of 1974 that bulldozer operator
George Hanson got the assignment of leveling a small hill for
landowner Phil Anderson. Anderson planned to build a housing
development on land near the town of Hot Springs, South Dakota.
As Hanson pushed the machine's blade into the hill, it hit something
buried in the ground. Getting out to take a closer look, he
saw what looked to be a seven-foot long tusk surrounded by animal
bones. He showed the bones to his son, who in turn contacted
Dr. Larry Agenbroad, a faculty member at Chadron State College
in Nebraska. Agenbroad arrived at the site a week later and
realized that he was seeing the bones of at least eight individual
But how had these mammoths, many in the prime
of their lives, come to die in such a small area? To understand
the mammoth trap it is necessary to go back in time to a period
230 million years ago. Great warm shallow seas covered much
of the middle of the United States. These seas were the domain
of the giant marine reptiles that
ruled the sea while the dinosaurs ruled the land. The bottom
of the sea became a layer of silt, sand and mud. When the seas
dried up, these sediments hardened to a red-colored rock called
Rock in this region was very susceptible to erosion
by water. Underground streams soon turned into immense caverns
(South Dakota today boasts two of the largest caves in the world:
Wind Cave and Jewel Cave). A large cavern room formed underground
where the mammoth trap is now located. Around 26,000 years ago,
the top of the room collapsed creating a steep, funnel-like
pit called a sinkhole. The water that had made the cavern now
pushed its way to the surface as an artesian spring through
a hole in the floor of the sinkhole. Water flooded the pit to
the depth of around fourteen feet. The water was warm, about
ninety-five degrees, so the sinkhole became an oval, one-hundred
and fifty-foot wide jacuzzi.
bones of a mammoth now exposed in the excavation.(Copyright
Lee Krystek, 2000)
The water and the vegetation that sprang up around
the hole made it an attraction for wildlife. As the Spearfish
shale that lined the sides of the pit became waterlogged, it
began to ooze like mud and crumble. Smaller animals that entered
the pit escaped successfully, but the heavy, awkward mammoths
could not get a firm enough footing to climb out of the sinkhole
once they had entered it. They either died of starvation, or
got so weak that they could no longer hold their heads up out
of the water. Sliding under the surface, they soon drowned.
Their remains sank to the bottom of the pit where silt and sand
covered and protected the bones. Scientists estimate that the
sinkhole acted as a trap for as long as seven hundred years.
In that time it is estimated that over 100 mammoths died in
While three of the animals were woolly mammoths,
the majority found have been Colombian mammoths. Colombia mammoths
were slightly larger than their well-known cousins, the woolies
with no hair. They resembled a modern Asian elephant with the
same small ears, but were larger and taller with longer tusks.
Mammoths were not the only creature found in the
trap. In 1983 paleontologists unearthed the skull of a giant
short-faced bear. The giant short-faced bear was one of the
most powerful predators of the Ice Ages. Thought to be omnivorous,
eating both meat and vegetation, the fearsome creature was thirty
percent larger than the modern grizzly bear and weighed 1,400
pounds. Standing some five-feet high at the shoulder when even
on all fours, the animal looked more like a cat than a bear.
It had a short snout and long, lean legs. It was probably attracted
to the pit by the scent of dying mammoths. Why it could not
climb out is a bit of a mystery. The bear's agile legs and sharp
claws should have enabled it to climb the slippery slope. This
has led some researchers to speculate that the bear was attacked
by a bull mammoth defending its herd. The bull knocked the predator
into the pit. Injured, the bear could not climb out.
After about 300 to 700 years the Mammoth Trap
became completely filled with bones and sediment. As it dried
out the sinkhole fill turned to stone. This stone was more resistant
to erosion than the Spearfish Shale around it and the sinkhole
eventually became the site of a small hill. It was while trying
to level this hill that dozer operator George Hanson exposed
the first mammoth remains.
By 1975 it became clear that the ancient sinkhole
was of great scientific value and the landowner, Phil Anderson,
decided to sell the ground at cost to the newly-created Mammoth
Site of Hot Springs South Dakota, Inc., a non-profit organization
formed to care for the site. In 1986 a 20,000-square foot building
covering the entire sinkhole was opened. This allowed for year-round
excavation and viewing of the site. The decision was made to
leave many of the specimens in the rock so that visitors could
view the remains just as they had been found. Concrete paths
were constructed around the edges of the ancient pit and across
sections of it. In between the trails visitors could peer down
into the excavations which are arranged like steps with many
deepest part of the excavation at the Mammoth Site in
South Dakota. (Copyright Lee Krystek,
When a vistor first observes the site bones seem
to litter the excavation at every level. Oval, flat-topped fossils
with peculiar ridged surfaces that look like the bottom of pairs
of tennis shoes stick out of the ground. These are the mammoth's
teeth set in their heads or jaws. In several places six-foot
long tusks still lie connected to massive skulls. So far the
remains of over 50 mammoths have been found in the pit.
Probably the most striking image at the excavation
is "Napoleon," the remains of a male Colombian mammoth
that stood about thirteen feet high. His completely-articulated
skeleton lies in the deepest section of the dig. The creature
was found lying on its back with its head pulled over the right
shoulder by the massive weight of its tusks. Not only were Napoleon's
bones found, but also bile stones, which are similar to human
kidney stones. Scientists estimate that Napoleon was almost
50 years old when he died.
Bore holes drilled in the middle of the excavation
indicate that the sinkhole may have been over sixty-five feet
deep. If this is the case, over fifty mammoths may still lie
beneath the ground inside the trap. Scientists hope that by
studying the remains they may be able to answer many of the
questions we have about these giant creatures. Perhaps even
the ultimate mammoth question: Why did
they die out?
Cyclorama: The Mammoth Trap
Krystek 2000. All Rights Reserved.