A Wyoming Cave Gives Up Its Ice Age Secrets

Natural Trap Cave in north-central Wyoming is a graveyard cavern that dates back to the Pleistocene period. Tens of thousands have died there, the bodies left exposed at the bottom of a hole. Discovered in 1970 and covered by a metal grate to protect lives and paleontological resources, it contains the fossils of animals which lived in the Americas at the time of the last Ice Age.

From the surface, the Wyoming cave doesn’t seem like much; it’s a 15-foot hole in the ground. Its deceptive appearance has, over the last 23,000 years, meant death to the unwary. The cave’s bottom is covered by a layer of the dead measuring 33 feet (10 meters) deep. It’s an 85-foot (26 meters) drop, lethal to all but the smallest of featherweights.

It's an 85 foot drop to the bottom of Natural Trap Cave
Sealed 30 Years Ago, Natural Trap Cave Hides Under Desert Scrubland.

At the bottom, it’s much larger than its entrance. At 120 feet (34 meters), its bell-like shape is carved into the Madison Limestone near Lovell, Wyoming. The karst cave is located in Bighorn Canyon National Recreation Area and was formed by water erosion. It’s the perfect location for unlocking the secrets to a world that disappeared 10,000 years ago. The cave is like a refrigerator, cold and damp, an environmental condition that has preserved genetic material which might hold the key to understanding the Pleistocene period and the extinction event which wiped out North America’s megafauna.

Des Moines University paleontologist Julie Meachen told Reuters that:

“Some bones still have collagen with intact DNA for genetic testing and some fossils are fragments crushed by rocks. But we take it for what it is when we find it.”

An international team of researchers and assistants led by Meachen have just finished the first of three annual digs at Natural Trap Cave and a few interesting things have come to light. Hundreds, in fact.

The team spent two weeks rappelling down into the sinkhole cave to explore its ancient body count. They excavated countless microfossils of small creatures such as birds and reptiles and removed 200 bones from large animals such as horses, grey wolves, bison, and the American cheetah.

Ancient species, long extinct, lay in Natural Trap Cave.
The Bones of The Dead Litter The Cave Floor in Wyoming

Buckets of artifacts made their way to the surface and were sent to university labs for analysis before the metal grate was dropped back into place over the cave’s mouth. Next year, the team will return for the second excavation but the bones of extinct animals won’t be all they are studying.

Two animals fell from the surface into the cave during the expedition. One, a deer mouse, survived and was nursed back to health. A pack rat was not so lucky. Its body was left at the bottom and will be studied over time, to measure the decay rate of its flesh.

In the past, scientists that have explored the cave have found the fossils of camels, short-faced bears, and mammoths — all animals that are extinct in North America.

The excavation took two weeks.
A Team of Researchers From Several Universities Gathered To Work At The Wyoming Cave.

This year’s dig, funded by National Geographic and started on July 29, has given its researchers a wealth of data that will take years to decipher. CNN news agency reports that Meachen and her team didn’t know what to expect when they first entered the cave.

“We hadn’t been there in 30 years and we didn’t know what the cave would be like.”

Scientists made multiple trips down into the cave to collect fossils.
Rappelling Into Natural Trap Cave, Scientists Were Anxious About What Waited Below

Using latex gloves and breathing masks, the scientists excavated prehistoric bodies, being careful to not contaminate the samples. The fossils were packed in coolers and shipped to several U.S. universities and the University of Adelaide, in Australia. They hope to find new insights into the Pleistocene climate and the genetic diversity and diets of animals that died out in the last Ice Age, more than 10,000 years ago.

Fossils from the Pleistocene period are found in layers.
Researchers Shift Through Layers of Dirt and Rocks To Reveal Ancient Dead

The scientists live-tweeted their work at #ntcave14, posting photos and video clips for the public. With a chance to explore Natural Trap Cave, they could hardly do anything less. Armchair paleontologists are following the research with excitement.

Further explorations of the cave may reveal a treasure trove of natural history dating back 100,000 years, an unprecedented find which might give the world rare glimpses into a lost world.

[Image Courtesy of the Bureau of Land Management]