Danielle Alberti

To the modern Boulderite, it may be difficult to imagine camels walking down Broadway—their hooves treading the ground that became CU. But according to recent archaeological finds, that visual just might not be as absurd as it sounds.

With a recent discovery of a cache of stone tools in a Boulder backyard, CU anthropology professor Douglas Bamforth has proven that humans and camels used to coexist in Boulder, albeit not very peacefully. The collection of 83 tools dates back to the Clovis Era, about 13,500 to 13,000 years ago, when many archaeologists believe the first humans were beginning to appear in North America. Only the second Clovis specimens to be analyzed for mammalian DNA, they are the first to reveal protein residue from camels. Analysis also shows evidence of horse, bear and sheep hunting.

The Mahaffy Cache is named for its owner, who discovered them while landscaping his backyard.

"They were just shoveling, and there was this 'clink,'" Bamforth said.

The tools show amazing variation. Coming in all shapes and sizes, they were carefully designed to fit every need a hunter-gatherer may have had. Some are perfect for slicing through the hide, while others will slice through the membrane that connects the hide to the meat. Others will cut the meat for cooking, while still others can scrape the hide clean to be used for other things.

The variation is also evident of the hunter gatherer lifestyle, showing how the clans migrated with the herds. The stones used come from several different areas of the Northern US. This shows that the people who created and used these tools likely didn't stay in one place for prolonged periods of time, but rather, would follow the food. This was important in a time prior to organized agriculture.

Archaeologists say it's unclear why the astounding collection was buried there so many years ago, in a hole the size of a shoe box.

"It might have been storage, like insurance. Leave them now, come back later," Bamforth said. "Or it could have been to lighten the load. Kill a camel, get rid of some rocks, carry some meat."

Dating stone artifacts isn't an exact science. Without any organic matter, it's impossible to run entirely reliable diagnostic dating processes.

The Mahaffy tools are thin and precise in their utility. Several are bifacial—carved on both sides. It's a skill that very few modern toolmakers have replicated.

"The general characteristics of the technology here are consistent with the kind of stone working people did then," Bamforth said. "We don't have any pieces that say, you know, 'Hi, I'm 13,000 years old.' But the quality of the stone working can make a case for their age. It requires immense skill."

Mahaffy, president and CEO of a Boulder pharmaceutical company and proud owner of the cache bearing his name, paid to have the tools tested in a high-end California crime lab. Four of the 83 tools tested positive for mammalian protein residue, pinpointing it down to the taxonomic family. They were able to identify camel, horse, sheep and bear on three separate analyses. Rabbit appeared on one test, but the result was weak and couldn't be replicated, indicating a false positive.

"It took us a long time to release this story because we kept waiting for elephant DNA. These people were known for hunting elephants," Bamforth said. "But usually, when you call a zoo and ask for a vial of their elephant blood to test against, they tend to hang up on you."

The tools did not test positive for elephant, but the real findings while unable to provide an absolute age, provided some insight based on historical context.

"There hadn't been horses or camels in Boulder, at least until white folks showed up, since the end of the ice age," Bamforth said.

While camels are most commonly associated with sand dunes and pyramids, evidence shows that the prehistoric mammal actually evolved in North America. Around 20 million years ago, they were grazers on the Great Plains and resembled the modern giraffe, with an elongated neck. They began to migrate over the Bering land bridge around four million years ago, evolving into the dromedary and bactrian camels we know today. Some stayed behind only to later encounter humans and eventual extinction, though it's unknown whether the two events are related.

The tools will be sent to Australia for additional DNA testing, and Bamforth is expecting a new microscope that will allow him to examine the larger implements in greater detail. After his study is complete and published, he will return the tools to Mahaffy.

Mahaffy has said that he plans to donate most of the specimens to the CU Museum of Natural History, located about six blocks from his home. Of the remaining tools, some will go on display inside his house while the rest will go back into the ground. It is not uncommon for archaeologists to replace certain artifacts (particularly human remains) back in the ground out of respect for the people who buried them.

"I can't blame him for wanting to keep them," Bamforth said with a grin. "They're pretty cool."