Back at the Denver Museum of Nature & Science, crews that spent a month of frenzied fossil discovery at a 130,000-year-old muddy lakebed near Snowmass Village are finding their ice-age treasure even more magnificent than previously revealed.
Museum workers — 67 individuals — recovered more than 500 bones representing eight to 10 American mastodons, four Columbian mammoths, four ice-age bison, two deer, Colorado’s first-ever Jefferson’s ground sloth and several smaller animal species, and hundreds of pounds of plant material.
Museum staff, having washed, sorted and transported the remains, revealed the latest, most impressive body count at a museum news conference Thursday morning.
“Our museum is changed forever,” president and chief executive George Sparks said. “Careers and lives are changed.”
All of the museum’s 450 employees and about 1,600 volunteers have supported this effort so far, he said. And analysis of the finds is just beginning.
Over time, paleontologists have pieced together a picture of the recent ice age from isolated sites around the world — from a mammoth femur from one state and another bone from another country, and so on.
At Ziegler Reservoir, scientists uncovered a whole ice-age ecosystem, spanning tens of thousands of years and marvelously preserved at an elevation of 8,874 feet, an altitude that had been mostly absent from the fossil record.
“We know almost nothing about what the Rockies were like during the ice age. We have our first clear window into it,” museum curator Kirk Johnson said. “It is one of the most amazing finds in North America.”
Scientists believe they can recover well-preserved DNA from these bones.
And they are planning to go back to Ziegler Reservoir to retrieve more in the spring.
Johnson said the site holds answers about many different species living at the end of the last ice age, a time of ancient global warming.
It is relevant today because “we live in a warming world right now,” he said.
The fossils were found during expansion of Ziegler Reservoir for a greater supply of snowmaking water for the nearby ski area. On Oct. 14, bulldozer driver Jesse Steele discovered the bones of a juvenile female mammoth and was “fossil-savvy” enough, Johnson said, to realize it was a eureka moment.
“They never thought they’d unearth an ice-age menagerie,” Johnson said.
On one of the last days on the dig, scientists found “a bone bed,” a debris slide with more than 80 bones.
Fossil and reservoir excavations are both expected to wrap up in October 2011.
Now it’s time for analysis, preservation and some early exhibition, Johnson said.
Scientists have in house 15 tusks of mammoths and mastodons — one still bone white — plus two tusk tips and 14 bags of tusk fragments.
One tusk is 8 feet long. These distant ancestors of elephants were massive, with Columbian mammoths standing 12 to 14 feet at the shoulder and American mastodons 10 feet at the shoulder, museum curator of paleontology Ian Miller said. Both species weighed 8 to 12 tons as adults.
The sloth, described as the most surprising find of the site, was the size of a full-grown grizzly.
Museum education expert Samantha Sands already has spoken to 8,500 schoolchildren in the fossils’ home territory, the Roaring Fork Valley. And 3,500 people turned up last weekend at Snowmass Village for “Mammoth and Mastodon Madness.”
Next fall the Denver museum breaks ground on its new 60,000-square-foot, climate-controlled storage facility, already in the works before this treasure trove was raised.
It’s looking like even a smarter idea now, Sparks said.
Electa Draper: 303-954-1276 or edraper@denverpost.com
Found at the site so far
You can see the bones at the Denver museum
Bones unearthed at Ziegler Reservoir have been on display in the Roaring Fork Valley periodically since Oct. 14. Front Range folks can get a look from 10 a.m. to 5 p.m. Saturday during “Mammoth and Mastodon Madness” at the Denver Museum of Nature & Science, 2001 Colorado Blvd. in Denver.
