Early North American humans may have left clues at Denver site

DENVER – Molly the Columbian mammoth lived, grazed and died about 13,000 years ago near a spring in what is now a fast-developing chunk of Douglas County. Five thousand years later, early North American humans spent time at the same spring, where they killed and butchered bison.

We don’t know if humans visited the spring at the same time as Molly, but if the Lamb Spring site produces evidence that they did – and it tantalizes with hope – the site could rewrite the scientific and cultural history of North America. And perhaps offer the Denver area a new attraction.

Lamb Spring sits in the Chatfield Basin, between South Platte Canyon Road and Chatfield Reservoir.

“Stand on that site (Lamb Spring) and look around. You realize you are in the middle of one of the fastest-developing areas in Colorado,” said Jim Walker, southwest regional director for The Archaeological Conservancy, an Albuquerque nonprofit that buys archaeologically promising land and safeguards it from development.

The conservancy bought the Lamb Spring site in 1995.

“The fact that we were able to find that site, buy it and preserve it, at the time we did, was a miracle. I’ll bet within 10 years that area is going to be covered in houses,” he said.

Walker believes further excavation of Lamb Spring could show human activity between 13,000 and even 25,000 years ago, in which case “there would be a lot of rewriting of the peopling of North America.”

“I would place Lamb Spring really high, in terms of its importance,” he said. “If I were ranking Lamb Spring among the other 450 preserves we have, it would be in the top 10.”

Evidence of Pleistocene megafauna such as mammoths makes the Lamb Spring dig compelling in its own right, but mammoth sites pepper the West. Early-human findings, in contrast, are rare. Placing both in the same location sets Lamb Spring – the largest “mixed dig” in the country – apart.

The findings may do more than just embellish what we already know: that humans roamed North America as far back as 11,200 years ago. Some archaeologists believe Lamb Spring could provide solid evidence, instead of just speculation, that people lived in North America much earlier.

Today, the Lamb Spring dig amounts to little more than a weed-choked and trash-sprinkled depression in the ground, a cavity surrounded by 35 acres of undulating, fenced-in prairie. An informational plaque sits beside the gated dirt path that leads to the site. Once a week for half the year, people can watch a video about the site and then follow a tour guide to the swale to observe the grass.

If it weren’t for a rancher’s desire for a stock pond 50 years ago, the bones of Molly and 30 other mammoths – the largest find in Colorado, and the third biggest in North America – would likely remain buried. But in 1960 Charles Lamb decided to use a spring on his land to make a fishing pond, and while digging, he struck some big bones. Geologists identified them as mammoths.

In 1981, Smithsonian Institute archaeologist Dennis Stanford excavated the site and found many more mammoth bones, as well as camels, horses, sloths, llamas and wolves.

Stanford also found a 30-pound rock. Marks on the stone suggested it had been used as a butcher block. Geological forces could not have brought the stone to the site. Instead, Stanford theorized, early humans must have done it, and based on its location in the sediment, that could have happened 16,000 years ago. If the theory can be proved, it will mean humans dwelled at Lamb Spring at least that long ago.

“I think Lamb Spring could yield what would be a jackpot – a campsite or village,” said Walker. “That would be incredible.”