Mammoth Find Gives Glimpse Of Rockies In Ice Age

Enlarge this image toggle caption Heather Rousseau/Denver Museum of Nature & Science Heather Rousseau/Denver Museum of Nature & Science

A slew of fossilized mammoths, mastodons and other Ice Age creatures have been turning up at a dizzying rate in western Colorado.

Researchers think this might be one of the most significant finds of its kind to date.

The credit for this find goes to construction worker Jesse Steele, who says he pretty much "grew up on the seat" of a bulldozer. Last month, he was working on a typical municipal project expanding a reservoir near the Aspen/Snowmass ski resort.

"I was stripping the peat moss and noticed a couple of rib bones come up in the load of dirt up in front of me," Steele says. "And at that point I stopped and got out and looked at them."

It was clear this was something big.

"It was kind of scary," Steele says. "I guess it made me nervous right at first. The bones didn't look like bones."

Enlarge this image toggle caption Courtesy of the Denver Museum of Nature & Science Courtesy of the Denver Museum of Nature & Science

Steele says they were so well preserved that it gave him an eerie feeling. But then the excitement kicked in.

"It is a Columbian mammoth," says archaeology grad student Brendan Asher, one of 40 researchers from the Denver Museum of Nature & Science who have descended on the site.

With a well-practiced motion, Asher takes a trowel and slowly and ever so tediously slices away the surrounding earth to expose the skeleton of the mammoth.

"Essentially what we're doing is shaving off, millimeter by millimeter, very thin levels [and] layers to expose what's below and potentially to uncover more bone as well as to hopefully find evidence -- potentially find human interactions -- with this animal," Asher says.

Identification Of 22 Species

Compared with other finds in North America and Siberia, this site is more complete and detailed because it includes insects, plants and animals.

So far, scientists have identified two time periods at the site -- one 12,000 to 16,000 years old and another more than 40,000 years old.

Enlarge this image toggle caption Rick Wicker/Denver Museum of Nature & Science Rick Wicker/Denver Museum of Nature & Science

"We've got partial skeletons of many a mastodon, of two mammoths, a couple of bison -- including the skull, a magnificent skull, of a gigantic Ice Age bison with a 7-foot horn span," says Kirk Johnson, the chief curator at the Denver museum who is overseeing the dig. "We have the bone of Jefferson's ground sloth, which is the highest known occurrence of this animal ever found in the world. And we've got a complete skeleton of an Ice Age deer."

And the list goes on. So far, the researchers have identified at least 22 animal species.

The Highest Ice Age Site

Scientists aren't certain why the remains of so many animals ended up at the site over such a long period of time. Johnson says the fact that this site is on top of a mountain -- rather than at the base -- means less sediment covered the bones as time passed.

"This is the highest Ice Age site," Johnson says. "And it will tell us a lot about what life was like in the Rockies during the last Ice Age. It's a window into an Ice Age ecosystem. We know very little about places like that, so this is really a world-class fossil site."

Researchers have spent the past month scrambling to get what they could out of the ground before winter set in. Now, they're moving the bones from the dig site to Denver for further analysis.

And with what they've found so far, they expect to be back when the ground thaws in the spring.