About 13,000 years ago, two adults and child walked barefoot alongside the Pacific coast shore of what’s now called Canada. This anthropological finding was announced Wednesday in PLOS One and made possible through radiocarbon dating. The researchers behind the discovery contend that it supports the hypothesis that humans used a coastal route to migrate from Asia to North America during the last ice age.

Although it’s widely accepted that humans migrated to the Americas via the Beringia land bridge, anthropologists are still not positive with how exactly they dispersed once they crossed to the other side. In this new paper, researchers from the Hakai Institute and the University of Victoria, Canada argue that evidence of ancient footprints indicates that during the last ice age, people eventually reached the west coast of British Columbia, as well as other southern coastal regions.

“This finding provides evidence of the seafaring people who inhabited this area during the tail end of the last major ice age,” lead author Duncan McLaren, Ph.D. in a statement released by PLOS One on Wednesday.

Calvert Island, British Columbia
The excavation site, Calvert Island, is in the foreground.

Investigations at the shoreline of Calvert Island, British Columbia revealed a total of 29 footprints of at least three different sizes. As anyone who has walked on sand knows, most footprints typically and quickly disappear: However, in cases where a print is left in soft sediments, a trace of the foot and the motion that placed it there can remain. Because of tides and waves, coastal settings are complete with soft and semi-saturated sentiments — meaning that evidence of animal and human movements can get trapped.

ancient footprints
Digitally-enhanced images of one of the tracks. 

Today, the sea level surrounding Calvert Island is two to three meters lower than it was at the end of the last ice age, and the beaches are covered by a dense forest. It’s only accessible by boat, which has made it difficult for archeologists to get in a survey. However, this team was able to get in and discover what they write are “clearly human tracks” — an obviousness indicated by a “clear arch, toe, and offset heel attributes.”

Radiocarbon dating indicates the 29 footprints are around 13,000 years old, while measurements and digital photographs of the prints show the prints likely belonged to two adults and a child.

These footprints, the study authors write, add to the “growing body of evidence that early peoples in the Americas inhabited the coastal margin and circumnavigated the western edge of the Cordilleran Ice Sheet to move between Beringia and mid-latitude North America at the end of the last ice age.”

This body of evidence contradicts the alternative, and some might say outdated, theory that the settlement of the Americas happened via an interior route within an ice-free corridor. Scientists keep encountering earlier, and earlier evidence of humans in the Americas — a lineage that likely connects to these three early humans who walked along the sand.