LAWRENCE — The area of water between Russia and North America and the Pacific and Arctic oceans is now known as the Bering Strait. Yet it was once what we call the Bering Land Bridge, an exposed land and maritime region that connected Asia to North America.
The Bering Land Bridge formed 35,000 years ago, eventually disappearing under rising sea levels around 12,000 years ago. But the humans and creatures who inhabited the territory have left behind plenty of archaeological evidence of their presence.
"It's fascinating to me how people have evolved and how our meager beginnings as hunter-gatherers have led to where we are now," said Kelly Graf, professor of anthropology at the University of Kansas.
Graf is part of a team of researchers who have spent years studying this region, leading to a new article titled " Highlights from an early base camp in Beringia 13,800 years ago: Shég' Xdaltth'i' and the Late Pleistocene Peopling of Alaska." This site in Alaska contains three early archaeological components dating to 13,800, 13,000 and 12,700 thousand years ago, revealing important information about late-glacial peopling and settling-in behavior in this far northern setting. The article appears in Science Advances.
The name Shég' Xdaltth'i' (pronounced shehg xuh-tuhl-th'ee) means "they were there" in Alaska Native Athabascan.
"The site is on a small ridge that overlooks the Tanana River, which is a major river system of the region. Today there are spruce trees all around. During the last part of the Pleistocene — the Ice Age — it was covered by shrub-tundra vegetation," said Graf, who co-wrote the paper with Ted Goebel, KU professor of anthropology and department chair; KU doctoral student Mia Harbort and KU undergraduate Mason Sewing, along with other academics from the U.S. and Europe.
Graf said Beringia is full of evidence showcasing the hunting of megafauna.
"Like at Shég' Xdaltth'i', they hunted mammoth, bison and horse. Those three particular sorts of animals are extinct now. But then they also hunted caribou, which is extant today. Indigenous people in Alaska today hunt caribou. It's a really important resource for them, and it always has been," she said.
Beringian archeological occupations are concentrated in an area slightly larger than the U.S. state of Maryland. The professor began making the lengthy trek to the Shég' Xdaltth'i' site in 2013, visiting every year until the COVID-19 pandemic. She has since been back in 2021, 2023 and 2025. In addition to being the director of the excavation project, she also secured several National Science Foundation grants totaling $400,000.
More than 80,000 archeological specimens were found during her excavations. These yielded an array of cultural remains, including a unique hafted-biface form, osseous tools, diverse fauna and well-preserved activity areas.
Among her favorite items found was a large stone anvil.
"It was sitting within a dwelling feature, and all around it were really bashed-up bison bones. And there were a lot of quartz and quartzite-rock hammerstones — which were the hammers they used to break the bones. So we think they were using these stones to fully process the bones to extract marrow and likely to render grease. This was all happening near a large earth oven," Graf said.
Other key finds include bird bones used to fashion needles and numerous diamond-shaped bifacial points, which she said were perhaps the sharpened tips of weapons.
"It's the only site in Alaska that features this clear diamond shape. And the only other places at this time that have such points in a northern context are on the Russian side of the land bridge. It suggests people traveled across the Bering Land Bridge to and possibly from this location," she said.
The professor has been at KU since 2022. Her expertise is in Ice Age archaeology, environmental archaeology and the peopling of the Americas.
"I remember taking North American archaeology during undergrad. I fell in love with the Bering Land Bridge concept: People hunting megafauna and traveling from one massive continent to another across exposed continental shelf. Studying extinct animals and the tools hunters used to take these animals. I just got caught up in the 'wow' of that," she said.
Graf noted the importance of studying the evolution of humans and their environment. What started as a mere handful of individuals in a small region expanded to over 8 billion in just a fraction of geological time.
"The past informs us on how humans have adapted and responded to life's exigencies," she said. "The more we learn about the evolution of the Homo sapiens species, the more we can understand ourselves today."
