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Snowmastodon site fossil excavation
At the Snowmastodon site Denver Museum of Nature & Science conducted its largest-ever fossil excavation, yielding a treasure trove of well-preserved Ice Age fossils. click to view MORE images...

The Snowmastodon Project at the Denver Museum of Nature & Science

In October 2010, just after the inaugural National Fossil Day, a sharp-eyed bulldozer operator working near a Colorado ski area uncovered the bones of a young female mammoth. Over the next 10 months, the Denver Museum of Nature & Science (DMNS) conducted the largest excavation in its 112-year history, yielding a treasure trove of Ice Age fossils. Museum crews uncovered 5,500 bones of 41 kinds of animals, including mammoths, mastodons, ground sloths, tiny rodents, camels, deer, horses, giant bison, even a tiger salamander! The quality of the fossils startled the scientists. A finely preserved series of high-alpine ecosystems had protected the specimens, a rare event, making this one of the most significant science discoveries ever made in Colorado.

This fall marks the second anniversary of the discovery of the Snowmastodon Project® site outside Snowmass Village, Colorado. A 40-member science team representing the DMNS, the U.S. Geological Survey, and academic institutions in North America and Europe are studying evidence from the site. Labs from California to England have samples of bones, plants, insects, sediment, and biomolecules. In June 2012, the scientists gathered for the first time since the excavation to share preliminary findings. The team will continue to study evidence from the Ice Age site until their collective results are ready to be published.

The science team is reconstructing a diverse ecosystem that will reveal what the Pleistocene looked like at high elevations in the Rocky Mountains. The Snowmastodon site was found in a buried eleven-acre lake and bog that existed during the Ice Age. Many of the fossil animals and plant species found have never been seen at that high of an elevation. The site was formed during a glacial period about 130,000 years ago, creating a moraine that in turn shaped and dammed the small lake basin. The lake and bog had neither a water inlet nor an outlet. Like a giant pickle jar, the liquid brine came only from rain and snow that fell in a catchment area of no more than twenty-five acres. Sediments in the ancient basin came exclusively from debris flows and from silt and finer sediments that fell over the area as windblown dust. These processes beautifully preserved this unique site and the spectacular specimens.

The DMNS conservation team examined and stabilized every bone pulled from the ground. The conservationists paid special attention to the water-logged state in which the bones were found. Fossils are typically not saturated in water for thousands of years. The team carefully air-dried the bones, checking the relative humidity daily, because drying the bones too slow results in mold growth and drying them too fast results in cracking. Preservation has been careful and intentional, and the specimens have reacted well to their post-excavation environment. All the loose bones are dried and numbered. Some of the mastodon and mammoth tusks remain in their plaster jackets to dry a bit longer because of their fragility. Every single bone is being closely studied and classified. Iconic specimens of a skull of the giant Bison latifrons, a claw from a Jefferson's ground sloth, and jaws from Columbian mammoth and American mastodon are now on exhibit at the DMNS.

DMNS scientists and volunteers are also meticulously searching for the tiniest Ice Age animals by picking through thousands of pounds of dirt and sediment from the site. The process involves rinsing the dirt through framed metal screens with millimeter-size openings. The water washes away most of the fine sand, silt, and clay, leaving behind a residue that is examined through a dissecting microscope to reveal the teeny treasures—hundreds of amphibian bones and rare fragments of mammal jaws and teeth with shiny enamel.

Public interest in the Snowmastodon Project has been among the most remarkable outcomes of the discovery. Open-house displays of the bones have attracted thousands of people. Teachers from communities near Snowmass Village were trained to participate in the dig and have since assisted with public outreach. The popular book Digging Snowmastodon by lead scientists Kirk Johnson and Ian Miller chronicles a first-hand account of the events that made the discovery an international sensation. The NOVA television special "Ice Age Death Trap," which follows the scientists as they race against time to complete the excavation, attracted 6.3 million viewers nationwide when it premiered on PBS.

The Snowmastodon Project is a testament to the need for continuing education and awareness of our nation's fossil resources. The bulldozer operator who unearthed the bones and recognized them as fossils may not have been trained as a paleontologist, but he apparently understood the significance of his find, which has become of immeasurable scientific and educational value.
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Mammoth partner feature articles:

Big Bone Lick State Park | Channel Islands NP, Pygmy Mammoth | Children's Discovery Museum of San Jose | Denver Museum of Nature & Science Snowmastodon Project | Fossil Discovery Center of Madera County | Kenosha Public Museums | The Mammoth Site at Hot Springs | Paleontological Research Institution, Museum of the Earth | The Tate Geological Museum at Casper College | Tule Springs Ice Age Park | Waco Mammoth Site

Last updated: September 14, 2012