The footprints of family members gathered around a hearth fire thousands of years ago on the central coast of B.C. may be the oldest ever found in North America.

The impressions left by the feet of two adults and a child in the soft clay of Calvert Island appear to be 13,200 years old, which would make them older than any others ever found on the continent, announced the Hakai Institute, a research organization that helped support the research.

"It was really quite exciting because with every brush of the trowel, you'd see toes appearing, or a heel or the arch of a foot," recalled University of Victoria archeologist Duncan McLaren, as he described the discovery to CBC's All Points West. "The hair on the back of our necks was standing up."

A footprint found on a B.C. island that may be 13,200 years old is seen in raw and enhanced (stained blue) images.

If the prints are as old as they appear, they are also the oldest evidence ever found of humans living along the coast of B.C., added McLaren. He and University of Victoria colleague Daryl Fedje led the archeological team that made the discovery.

The first footprint, pressed in grey clay that was covered with other sediments, was found late last year just as work was wrapping up for the autumn season.

A STEP BACK IN TIME from Hakai Magazine on Vimeo.

"We weren't actually too certain what we found, but we took some photographs, also took some samples of the sediment from within the footprint," he said.

Radiocarbon dating of two samples of material from the footprint showed it was 13,100 to 13,200 years old — older than any other evidence of humans in coastal B.C.

"We were very excited," McLaren recalled in another interview with CBC News. "To tell you the truth, we were a little bit surprised that we got such early dates."

12 more prints

The results prompted the team to return to Calvert Island to do a larger dig this past May.

This time, they found 12 distinct footprints belonging to a larger adult, a smaller adult and a child, and the remains of a hearth fire that the group — probably a  family — had been gathered around. The hearth itself was full of charcoal and ash and ringed by rocks, including a stone tool that would have been used for chopping or cutting, McLaren said.

Daryl Fedje and Duncan McLaren

Hakai Institute and University of Victoria archeologists Daryl Fedje (background, in red) and Duncan McLaren (foreground, in orange) led the dig on Calvert Island, on B.C.'s central coast. (Joanne McSporran)

It was a challenging project, he added, because the dig site was located in the intertidal zone. The samples were very old and fragile, requiring great care during the excavation.

"But at the same time the tide is coming in and will create havoc for us so it's always a little bit of rush against time."

Because the dig took place less than two months ago, the team hasn't yet had the chance to get radiocarbon dates for the other footprints or publish the results in a peer-reviewed journal. But McLaren said the team decided to go public with the results because it's an exciting find and journalists had been asking about it.

He cautioned that more work is needed to confirm the results, as material found a few metres away was just 2,000 years old. But he says he's fairly confident the footprints are closer to 13,200 years old because those dates came from the footprint material itself.

Dig site Calvert Island

The dig site is challenging to work at because it located in the intertidal zone, making excavation of delicate samples a race against time. ( Joanne McSporran)

The oldest human archeological remains ever found in B.C. are from a cave in Haida Gwaii, dating to about 12,500 years ago.

"This is pushing it back 700 years," he said. "It's quite a long period of time."

Migration by boat

McLaren says the find could provide key evidence about how the continent's first inhabitants migrated south. Older archeological remains have been found in both north of B.C., in Alaska, and south of B.C. in Oregon. It wasn't clear whether people moved from Alaska to Oregon by travelling inland on foot near the Rockies or along the coast by boat. But the new discovery favours the water route.

"There's no way to get to Calvert Island other than watercraft, and that applies to 13,000 years ago as it does today," McLaren said.

The team plans to do carbon dating on the new footprints to ensure they can duplicate their results. They are also dating the ash from the hearth and examining it under the microscope.

The research was supported by the Hakai Institute, a research organization funded by the private, non-profit Tula Foundation. Members of the local Heiltsuk and Wuikinuxv First Nations also participated.

To hear the full interview with Duncan McLaren, listen to the audio labelled 13,000-year-old footprints.