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Underwater investigation reveals ancient artifacts

Parks Canada archeologists are closer than ever to unravelling 13,000-year-old mysteries buried beneath the surface of Banff’s Lake Minnewanka.
Underwater archeologists prepare a core sampling tube used to extract sediments deep within the lake bed.
Underwater archeologists prepare a core sampling tube used to extract sediments deep within the lake bed.

Parks Canada archeologists are closer than ever to unravelling 13,000-year-old mysteries buried beneath the surface of Banff’s Lake Minnewanka.

A team of divers has been doing core samples and archeological test pits of a prehistoric campsite that has been underwater for up to 100 years; after the area was flooded when dams were built.

They’ve been looking to unearth more information about the condition and extent of the threatened 13,000-year-old site, of which a small strip first became exposed on the shores of the reservoir about 50 years ago.

And, on the last day of their underwater investigation on Oct. 26, the Ottawa-based diving specialists, discovered some artifacts at least 9,000 years old that gave them some of the answers they were looking for.

“This is very exciting. It’s not too often you get to work at a site this early; it’s one of only a handful known in the New World,” said Bill Perry, an archeologist with Parks Canada.

“The people here were some of the first people in the New World, coming over the Siberian land bridge. It’s 13,000 years of continuous use of people coming in and adapting to a changing environment over time.

“It’s therefore important to us to try to figure out what’s left of the site. We want to properly understand the site and record it before too much of it is lost.”

About 13,000 years ago, the last ice age was just receding and the environment in the Bow Valley was just starting to support life, and with the animals came the hunters.

For more than 100 centuries, people hunted and camped along the original shores of Lake Minnewanka. The Stoney people called it ‘Minn-waki’ or ‘Lake of the Spirits.’

The manmade changes to the lake and surrounding area began in 1895 when a dam was constructed on Devil’s Creek. A second dam was built in 1912 in Devil’s Canyon for water storage.

This dam raised the lake 3.5 metres, creating a new shoreline and flooding Devil’s Creek. The third and present dam, built in 1941, raised the lake another 30 metres, flooding the townsite there and the 1912 dam.

The rising waters also covered up the prehistoric campsite, but every spring during drawdown, a small strip is revealed along the edge of the reservoir.

This site has long been regarded as one of the oldest archeological sites in Alberta due to the discovery of a variety of Paleoindian projectile points, including Clovis points, on the eroded beach.

Tent rings and charcoal and rocks from ancient hearths have also been found at the site, as well as many sheep bones.

Perry said human history in the area dates back 13,000 years, but this fall’s underwater core testing and excavation work only took them as far back as 9,000 years.

Archeologists caught their first glimmer of hope on their last dive of the day on Oct. 24 – finding a red silt layer that acts as a time marker dating from between 7,000 and 9,000 years ago.

From there, they did more testing, discovering artifacts like burnt bones and stone flakes, a result of making stone tools like arrows and spearheads.

They then set up a one-metre by one-metre underwater excavation site just 21 feet below the surface, which would again reveal the artifacts they had been been hoping to find.

“This is telling us that 9,000 years ago people were making stone tools and cooking bones in fires and things like that,” said Perry. “We know overall from the site they were hunting and butchering and camping and living there.

“These were prehistoric hunters that were adapted to hunting primarily sheep. It’s known Rocky Mountain sheep range and archeologically it looks like it always has been. We’re finding sheep bones in the layers.”

The Parks Canada diving crew is the same one that last year located HMS Investigator, a British naval ship that sunk in the Arctic after it set out in the 1850s in search of signs of Sir John Franklin’s expedition.

Marc-André Bernier, chief of Parks Canada’s underwater archeology service, said diving in Minnewanka brought great conditions, including water temperature and visibility.

He said the divers, whose biggest challenge was trying not to overly exert themselves, were pleased to find the red silt layer, which led to the eventual discovery of the 9,000-year-old artifacts.

“Our mandate is to support protection and preservation of underwater heritage in the Parks Canada system, mainly within national parks and national historic sites,” he said. “So this is a very exciting project to be involved in.”

Perry said erosion is threatening this highly significant site.

“The erosional process is definitely scouring out a lot of the top layers in certain parts of the site,” he said.

“We would like to protect it and preserve it and tell the story to the general public. As public servants, we have an obligation to give this information back to everybody.”

The plan for next year is to try to go back to Lake Minnewanka and do further testing and core work.

It may even involve talking with TransAlta. A four-kilometre pipe carries water from the lake to the Cascade power plant – the only power development in a Canadian national park.

“That is definitely one of the things on our list, but generally what we will do is come up with a plan about how to deal with what’s left of the site,” said Perry.

“It all depends on what kind of partnerships we can get going and what kind of money we can access, but at a bare minimum, what we’re trying to do is extract as much information as possible before it’s lost.”

Rocky Mountain Outlook

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