Snowmastodon’s past and our future

Visiting scientist Noah Fisher and Gussie MacCracken work on a large mastodon scapula.

Visiting scientist Noah Fisher and Gussie MacCracken work on a large mastodon scapula. ©Denver Museum of Nature & Science.

Snowmastodon is about extinct species, but also about our own

by Allen Best

An amazing discovery occurred in 2010 about a quarter mile from the ski lifts of Snowmass. Scooping out a meadow to create a water reservoir, a bulldozer operator upended bones, a tusk and an eight-inch tooth of a long-extinct Columbian mammoth.

These were the first of 6,000 large fossil bones plucked from the mud, many of them, like the mammoth, of extinct species. But more than a graveyard for ancient elephants and other long-gone animals, the Ziegler Reservoir site provided an exceptionally transparent high-elevation window into climate change of the past and possibly a hint of future climate changes.

Now, town officials in Snowmass Village are trying to figure out what to do with information from this unique site. So should the rest of us. Snowmastodon, as the site is known, is not merely a curiosity from the past. It’s about vital issues of today. Any museum that Snowmass creates must figure out to look both backward and forward.

The big bones have been the easy, photogenic part of this story. With cameras ready, paleontologists and their volunteer assistants hoisted giant femurs, tusks and other fossils deposited between 77,000 and 140,000 years ago. There was a giant Jeffersonian ground sloth, as big as grizzly bears today, plus the horns and skull of bison antiquus, now extinct but half again larger than the buffalo that halt traffic in Yellowstone National Park. See that buffalo in the flesh and you’d want to have one of the magic-dealing insurance agents at your command.

It was most of all a cemetery for mastodons, like the mammoth, a species now extinct but related to elephants. Scientists call it the most significant mastodon site ever found.

At the hands of humans

Why did mammoths and mastodons became extinct? They might not have adapted to the climate well after the glaciers retreated roughly 14,000 years ago. By about 10,000 years ago they were gone from the North America mainland. Humans probably did them in. In places, including Colorado, spear points and other artifacts have been found with bones of extinct species of mammoths, horses and bison. It was a triumph of human ingenuity and technology and a tough-luck story for the species.

Photo by Heather Rousseau

Dr. Steve Holen, curator of archaeology at the Denver Museum of Nature & Science, stands behind a giant Ice Age bison skull unearthed at the fossil dig at Ziegler Reservoir. Photo by Heather Rousseau. ©Denver Museum of Nature & Science

Why were so many mastodons and mammoths entombed in the peat and clay at Snowmass? Humans were one suspect in this paleontological whodunnit. On a scorching day in July 2011, Gov. John Hickenlooper helped see off an assemblage of bones and rocks encased in a plastic sleeve for closer scrutiny by museum curators at the Denver Museum of Nature and Science. No explanation was given that day, but placement of the rocks over the bones had seemed odd to scientists. They wondered if this was evidence that the meat from a now-extinct elephant had been cached by humans.

Big news, if that were the case. An open question is when humans first arrived in the Western Hemisphere. Firm evidence of residency has established for 14,000 to 15,000  years ago. Some new evident suggests an earlier arrival. Remains at Snowmass were upward of 55,000 years old. So far, however, closer study of the rocks and bones has produced nothing.

Rather than the big bones, scientists from the beginning suspected that the greatest value of the Snowmass discovery would be the tiny stuff: seeds and pollen, and leaves still green and insects still iridescent after 100,000 years when first extracted from the peat. Rarely does climatic evidence of the past get so well preserved. This site has fidelity. The window was not smeared.

“It took me about five seconds to figure out that this was something unprecedented and unique and really something that I had never seen before,” said Jeff Pigati, a geoscientist with the U.S. Geological Survey, shortly after research about the discovery was published in a special issue of Quaternary Research, a professional journal.

Rapid climate change

Pigati says those proxies tell us that the climate at 9,000 feet in elevation during the last interglacial period didn’t march in lockstep with the global climate. When it got hotter globally, it got much hotter yet at higher elevations. You might say that when the Earth’s climate wobbled, the climate at Snowmass swung its hips.

The reverse was true, too. When the Earth’s climate chilled 87,000 to 100,000 years ago, it got distinctly colder in west-central Colorado. Treeline likely descended to below 9,000. It’s at 11,500 to 12,000 feet today.

Ian Miller, the chairman of the Earth Sciences Department the Denver Museum of Nature & Science, says that Snowmass demonstrates amplified response of mountainous areas. “This just drives home the point that the system responds dramatically (to climate change triggers) at higher elevations.”

Solar radiation patterns drove climate changes documented at Snowmass. Today, the greenhouse theory holds that humans themselves have been become agents of climate change, through both land-use changes and through gases emitted into the atmosphere.

But even without forcing climate changes, we humans have powerfully altered the natural systems. We probably did in the Ice Age elephants. Armed with guns, we quickly did in passenger pigeons during the 19th century. We then raced through the vast buffalo herds. By 1859, the year of the Colorado gold rush, a travel guide to the Great Plains predicted extinction of this “monarch of the prairie” within a few years. With arrival of railroads, expediting shipment of bones and hides, we nearly accomplished it.

In Colorado’s mountains, the voracious hunger of Leadville and other mining camps caused hunting that by 1910 had reduced the state’s elk population to 500 to 1,000. Severe hunting restrictions, creation of wildlife refuges and transplants from Wyoming helped bring back the species from the brink.

On into the next big extinction

This was small stuff in comparison to the extinctions now underway global. Most prominent among a host of books making this case is Elizabeth Kolbert’s “The Sixth Great Extinction.” As the title suggests, the Earth has gone through several mass extinctions. The reign of dinosaurs ended when an asteroid slammed into the Yucatan peninsula of Mexico, producing a thin grayish layer called the K-T boundary, evident in a road cut west of Trinidad and in the West Bijou open space east of Aurora. With dinosaurs gone, space was  created for humans to evolve.

Now, species are disappearing left and right, from itty-bitty things to the lingering elephants. We humans have a huge wake.

Ian Miller and Jeff PigatiGeologists tend to take the big-picture view. Species come, species go. My cousin, an oil-patch geologist, once asked me: “Well, why should we be any different?”

I guess it’s for the same reason that I start out every season harboring hope that the Denver Nuggets will finally get an NBA championship. Of course, I’ve been hoping since 1969, when they were Rockets in the old ABA and played in the Auditorium Arena on 15th Street. For all my preoccupation with dour subjects, I’m an insufferable optimist.

And maybe humanity, with all its cleverness, will pull a magical rabbit out of its technological hat. In “The Big Ratchet: How Humanity Thrives in the Face of Natural Crisis,” Ruth DeFries lays out the sequence in which civilization keeps coming to the brink of being unable to feed itself but then somehow pivots to greater production.

Of course, Gen. George Custer had 13 horses shot out from under him in his career as a risk-taking soldier and came up each time smiling. In Montana, his luck ran out.

The dilemma for Snowmass

What should Snowmass do with its great find? A report delivered to town officials in September outlined the challenges and opportunities in creating a museum.

Museums can be different economic propositions. A nice building isn’t enough, or even a powerful exhibit. Content must change.

Museums have also become more interactive. Putting bones and bullets under glass display cases isn’t enough. At the Oregon Trail museum in Casper, Wyo., you can walk on a treadmill while pulling a handcart as the Mormon trekkers did from the 1840s until the 1860s, to see if you can match their pace. At History Colorado, in downtown Denver, you can sit inside a replica house set in the Dust Bowl of southeast Colorado to see lights dimming and sand blasting.

I would hope a museum at Snowmass could help visitors squeeze the mud of Ziegler Reservoir, as I did in 2011. It was about an hour after Hickenlooper’s visit, and a backhoe operator was already deepening the pit. I scolded myself for not wearing a hat, as mid-day sun at 9,000 feet is intense and hair atop my head is well on its way to extinction.

With a personal tour by Kit Hamby, the general manager of Snowmass Water & Sanitation District, I was astonished to pull out leaves, still green, from before the last ice age. I squeezed the peat and clay through my fingers that had embalmed so many extinct species.

Can our species survive another 100,000 years by elbowing aside so many other species? That’s one essential question any museum in Snowmass worth visiting must address.

This essay was originally published in The Denver Post on Sunday, Jan. 4. 


About Allen Best

Allen Best is a Colorado-based journalist. He publishes a subscription-based e-zine called Mountain Town News, portions of which are published on the website of the same name, and also writes for a variety of newspapers and magazines.
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2 Responses to Snowmastodon’s past and our future

  1. Pingback: Snowmastodon's past and our future —

  2. Bob Didur says:

    Meteor Creator is dated at 50k years ago as is the the “meat cache”.
    As the crow flies distance is 363 miles.
    What affect would an impact of that size have on an existing human population?

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