Department

Buried Treasures

How Snowmass Village became the improbable—and mysterious—site of a fossil mother lode that may redefine Colorado’s evolutionary history.

May 2011

The unnatural pairing of mammoths and mastodons is only part of the puzzle at Ziegler. Why did so many creatures meet their end in this one spot? The answer may lie in the age and the location of the ancient lake. Lakes are what Johnson calls an “attractive nuisance” for animals; they feed, drink, and hunt at the water’s edge and occasionally drown or fall through the ice in winter. Over time, sediment carried in by rainfall or tributary streams fill a lake, trapping the remains.

Most lakes fill up in a few thousand years, leaving only a small number of fossils. Ziegler is confounding because it trapped so many. What’s more, sitting at nearly 8,400 feet with no tributaries running into it, Ziegler has no obvious source of sediment. Johnson speculates that eons of dust storms, along with earthquakes that freed debris from the walls of the lake, may be the culprits. The amazing preservation of such a variety of plants and animals—of widely varied ages—left even the experts scratching their heads, until they looked at a geological map of the area. It shows that the boundaries of this tiny lake were pushed into place by a moraine—a steamroller of earth and rock propelled by a glacier that carved its way through the landscape and deposited the incongruent remains. This particular steamroller is thought to be 130,000 to 150,000 years old, and the unique conditions mean hundreds of animals could be preserved in the lake.

It’s only a theory, Johnson says, but so far, it’s the prevailing one. As researchers learn more, Johnson expects “a jillion” more hypotheses. None of them will change the most important thing we already know about Ziegler: “Something happened here,” he says. “Whether it’s a crime scene or a cemetery, there are a bunch of cool things going on.”

Scientists will return to Snowmass in May to finish excavating the dam site before the reservoir is filled. Time is on their side because only one of Ziegler’s 11.5 acres will be disturbed to build the dam before filling it in with water. And that, Johnson says, is the best way to preserve whatever else lies beneath. Finding a series of sites at this elevation with such well-preserved remains makes it, Johnson says, the most noteworthy Ice Age find ever in Colorado. It’s potentially akin to the La Brea Tar Pits, whose asphaltlike sediment has entombed millions of Ice Age fossils and attracted about that many visitors, intrigued by the notion of a real-world Land of the Lost nestled in the heart of Los Angeles.

The Colorado mastodons are already exhibiting similar box-office appeal. The Denver Museum of Nature and Science has dubbed the ongoing excavation “The Snowmastodon Project.” Last year, the fossils attracted 3,000 visitors on the only day they were on display. And in Snowmass Village, the town has established a “Tusk Force” to help plot the future, which might include a museum. The town council has already declared Widespread Panic’s “Big Wooly Mammoth” the official town song. Locals have nicknamed the mastodon “Snowy,” and she’s become the unofficial mascot for Snowmass Village, the ski-town-cum-Ice-Age wonder that now sports banners bearing her likeness under the slogan, “I dig Snowmass.” And it’s all thanks to a bulldozer driver who had a keen eye and a keener sense of history. “We’ve really seen it resonate more than we ever expected,” Johnson says. “And what’s so amazing is it wouldn’t have happened if Jesse Steele hadn’t looked over the blade.”

Abigail Eagye is a freelance writer in Carbondale. E-mail her at [email protected].

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