Thousands of Artifacts Unearthed in Alaska Hint at an Even Older Human Presence in the Americas

Researchers in Alaska have discovered rare artifacts connecting prehistoric communities on either side of the famous Bering Land Bridge far earlier than previously believed.

In a study published Wednesday in the journal Science Advances , researchers describe an astounding amount of archaeological material unearthed over more than a decade at Shég’ Xdaltth’í’, a 13,800-year-old archaeological site in interior Alaska. Most notably, they discovered diamond-shaped projectile points that have previously only been found in two archaeological sites on the other side of the Berring Straight, in Russia.

This points to a connection spanning the famous bygone land bridge. These findings suggest that traces of an even older human presence in Alaska than previously believed might be waiting to be discovered.

The study is the result of more than a decade of work. “There’s just so much stuff,” Kelly Graf , an anthropologist at the University of Kansas, told Gizmodo. “As soon as we knew how cool it was, in the first few years, we wanted to be able to write a paper about it. But we were like, ‘No, we need to do this right.’”

Shég’ Xdaltth’í’ is close to Fairbanks, Alaska, and what sets it apart is how paleo-Indigenous people would have spent their time there. Many other known sites in Alaska from the same time period were short-lived “special task” camps, like hunting camps, so archaeologists have been on the lookout for a “base camp”—essentially a larger group’s longer-term headquarters with evidence of daily life, as opposed to a single use site.

Shég’ Xdaltth’í’ seems to be that base camp. While researchers found multiple archaeological layers, the one that corresponds to the base camp is the oldest and dates back to 13,800 years ago, though some material might be 14,000 years old. The layer yielded an exceptional quantity and diversity of material. The team found thousands of artifacts in less than 11 square feet. They unearthed tools and a wide variety of animal bones, as well as what appears to be a pit and a hearth inside of a dwelling, among other features.

The tools included an anvil, hammerstones, and the aforementioned diamond-shaped projectile points—a shape that hasn’t appeared in any of the other Alaskan sites. But archaeologists have found this same diamond-shaped style in two sites from the same time period on the other side of the Berring Land Bridge, in modern-day Russia.

During the last ice age, sea levels were low enough that the north-western tip of Siberia and the north-eastern tip of North America were connected by a now-submerged region called the Bering Land Bridge . While “land bridge” suggests some sort of highway, it was really just a region of land like any other. Scientists once thought that the first North Americans arrived from modern-day Russia via this land bridge, but the currently widespread “coastal route theory” indicates that humans arrived significantly earlier via boat.

Either way, the presence of diamond-shaped projectiles at Shég’ Xdaltth’í’ “mirrors what’s going on on the western side of the Bering Land Bridge,” said Graf.