Tracing the Remains of a Founding Society in North America

Traveling south on Oregon Highway 31, it would be easy to drive right past what has recently become a place of international intrigue. In a westward-facing, rock-laden outcropping rising from dry soils just southeast of the picturesque twenty-mile-long Summer Lake are the Paisley Caves, an archaeological site now stamped into North American history.

Earlier this year, archaeologists led by Dennis Jenkins of the University of Oregon’s Museum of Natural and Cultural History, announced that they had found the oldest directly dated remains of people in North America. The team located obsidian spearheads dated to 13,110 years ago and human DNA in coprolites, or dried feces, dated to 14,300 years ago, providing evidence of a culture (Western Stemmed Tradition) that shared the continent with that of the Clovis people about 13,000 years ago.

“The colonization of the Americas involved multiple technologically divergent, and possibly genetically divergent, founding groups,” the UO-led team concluded in their report published in the journal Science.

The spear points left behind in the Paisley Caves, researchers concluded, belong to the Western Stemmed Tradition and are unlike the fluted projectile points used by the Clovis people––long considered the earliest North Americans.

The UO team identified human DNA extracted from coprolites. That discovery was initially reported in 2008 in the journal Science by Jenkins and international scientists who were experts in radiocarbon dating and DNA analyses. The DNA pre-dated any previously found human remains in North America, but some archaeologists challenged the 2008 claim, arguing that contaminants could have tainted the coprolites. In the years since, Jenkins and his team discovered additional artifacts and conducted more refined radiocarbon dating on fibers from the coprolites in a manner that removed any potential contaminants.

The findings announced this year resonated within the scientific community and were highlighted by more than 170 news outlets around the world, including The New York Times and National Public Radio. The report reinforced the theory that two different cultures existed for years in North America—one in the southeastern U.S., the Plains, and the southwestern U.S., and one in states further west.

Excavation of the Paisley Caves dates back to 1938 when UO scientist Luther Cressman, the father of Oregon anthropology, discovered artifacts associated with bones of bison, camel, horse, and other animals, but few researchers accepted the findings due to a lack of documentation. In 2002, Jenkins and the UO archaeology field school conducted new excavations at the Paisley Caves, partly to test Cressman’s theories.


Dennis Jenkins displays three bases for western stemmed projectiles from Oregon’s Paisley Caves. The bases date to 13,100 years ago.

The digs turned up artifacts in layer after layer of well-stratified soils, including an ash deposit left 7,640 years ago by the eruption of Mount Mazama, which created Crater Lake. Among the finds were additional camel and horse bones, projectile points, sagebrush rope,a wooden peg, and human coprolites.

While Jenkins has since sealed the Paisley Caves to preserve them for future generations and newer research technologies, he and his colleagues will continue to study the many artifacts they have found. Jenkins is currently writing a book about his work at the caves.

When asked about the legacy of the discovery, Jenkins says he has proved that Cressman’s long-debated conclusions were, in fact, rock solid.