Snowmass tally: 10 mastodons, 4 mammoths, one "once-in-a-lifetime" find

Denver Museum of Nature & Science chief curator Kirk Johnson today called the accidental discovery of an Ice Age fossil site at Ziegler Reservoir near Snowmass Village "one of those once-in-a-lifetime finds.


"Not only will it completely shape our understanding of life in the Rockies during the Ice Age, but it will become forever iconic for the kids of Colorado," said Johnson, who is also vice president of the museum's Research and Collections Division.

Heavy equipment operators excavating a reservoir unearthed a mastadon tusk Oct. 14, sparking a flurry of more precise digging that unearthed hundreds of specimens before the operation was shut down for the winter Nov. 2.

The tally so far includes:

* Eight to 10 American mastodons
* Four Columbian mammoths
* Two Ice Age deer
* Four Ice Age bison
* One Jefferson's ground sloth (the first ever found in Colorado)
* One tiger salamander
* Distinctly chewed wood that provides evidence of Ice Age beavers
* Insects including iridescent beetles
* Snails and microscopic crustaceans called ostracods
* Large quantities of well-preserved wood, seeds, cones, and leaves of white spruce, sub-alpine fir, sedges, seeds, and other plants.

The preservation of the fossils discovered at Ziegler Reservoir is exceptional. At least one of the 15 tusks recovered from the site is still white after tens of thousands of years, the museum said in a news release today. Scientists think there is a good chance of recovering well-preserved ancient DNA from some of the fossils.

Daniel Fisher, a mastodon expert from the University of Michigan and consultant to the Snowmass excavation said the high-altitude setting of the site — 8,874 feet — is underrepresented in the Ice Age fossil record.

"There have been suggestions that high-altitude environments might have harbored different communities, or had a different story of change, but since fossils representing them are so rarely found, no one has known for sure," Fisher said. "Now is our chance to see what they are like."

The age of the site is also of particular interest to scientists, the museum said.

Initial radiocarbon dating indicates that the Ziegler Reservoir site is more than 43,500 years old, and geologists estimate the site could be as old as 130,000 years. Additional analysis will provide more specific dating of the site.

OUR TURN TO LOOK:
Bones unearthed at Ziegler Reservoir have been on display in the Roaring Fork Valley periodically since Oct. 14. Front Range folk can get a look 10 a.m. to 5 p.m. Saturday, during "Mammoth and Mastodon Madness" at the Denver Museum of Nature & Science, 2001 Colorado Blvd., Denver.