Acient bison bones unearthed at Dead Man’s Flats are yet one more indication that North America’s largest mammal was at home in this mountain valley.
The bones, a femur and skull, were found during excavation work just below a layer of silt in late spring at the new River’s Bend subdivision.
The bones are not significant on their own, but the fact they were found at Dead Man’s Flats is significant.
“In the collections here at the Royal Alberta Museum (RAM) we don’t have a lot of records of that area of the province, so in that sense I see it as a significant record because it is starting to fill in the gap in our knowledge base, which is a good thing,” Chris Jass said.
The skull and femur appear to be from a modern bison (Bison bison), he added and based upon that, Jass said that puts the age of the bones within the last 5,000 years.
“The only way that we can get an age on it at this point would be to get a radio carbon date. My estimate is just based on overall size and preservation of the specimen and what we know of the geology of that particular area is that we are looking at something post-glacial in age and by that something that is younger than 11,000 or 12,000 years,” Jass said.
Modern plains bison emerged as a distinct species about 13,000 years ago as its director ancestor, Bison antiquus, began to dwarf in response to hunting pressure by people and environmental change, according to Trevor Peck, plains archeologist with Alberta Culture.
“Fairly recently, evidence shows that bison started dwarfing, probably about 13,000 years ago, and by 8,000 or 9,000 years ago it’s pretty clear that they were morphologically modern bison,” said Peck.
Bison antiquus, on average, stood over two metres at the shoulder and weighed about 1,000 kilograms. With its large size and formidable horns – perhaps two metres from tip to tip – Bison antiquus was designed to stand and fight.
But that made these giant bison easy prey for Paleo-Indians associated with what is known as the Cody cultural complex that spread throughout the Great Plains from Texas into Canada. These hunters excelled at hunting Bison antiquus.
Between the pressure of hunting and a changing climate, Bison antiquus began to change, developing smaller horns, more refined teeth and an instinct to flee. Their body mass also began to shrink.
“The ones who could eat better with their better teeth and were smaller and needed less to survive on and that could flee were the ones who were surviving. In other words, predation and a more hostile environment for the food they were getting was stressing them,” Peck said.
“They (Cody complex) were excellent bison hunters and they were putting this extra impetus on bison,” he said.
But as the bison changed, so too did the hunters. Taking advantage of the bison’s inclination to flee rather than fight, Paleo-Indian began driving the animals over cliffs.
“The second (bison) changed, people were onto it,” Peck said. “As soon as animals changed, people were changing right along with them.”
The bones found at Dead Man’s Flats exhibited no signs that they were killed and slaughtered by humans. Instead, both Jass and Peck believe death and subsequent burial came as a result of natural causes and processes, as the bones were discovered in the alluvial fan of Pigeon Creek.
Along with the bison bones, an unexpected find, Alberta Culture has been monitoring bucket tests undertaken as part of flood mitigation work in the MD of Bighorn.
Even though flooding does destroy homes and infrastructure, the floodwaters and the debris it deposits can be a beneficial process in terms of preserving archeological and paleontological sites, Peck said.
“You can see all the rock layers in there and that is all the different episodes of flooding,” Peck said pointing to a test hole in Harvie Heights located next to Grotto Road.
“An alluvial fan is like a delta on top of the ground. It’s like a dog wagging its tail. It could be over here and then move over there for a while. You can see it over there, but not necessarily here until flooding and then it changes its course and goes out into a fan shape into the valley,” he said. “For archeology, it’s great because we need the sediments to cover up campsites and things like that.”
The bucket test just off Grotto Road yielded bone fragments and thin layers of ash and paleolsol (ancient soil). Fire broken rock, associated with a hearth, was found at a bucket test site near Lac des Arcs.
Ash, which can either be from forest fires or volcanic eruptions, can be crucial time markers, Peck said, including the Mount Mazama eruption about 6,800 years ago that created Crater Lake in Oregon.
“This is a crucial time marker. In that sense, it’s a good way to know where you are in the time. The other thing that is really interesting about that ash landing is we have a pretty good understanding of what people were doing on the timeline and right after that ash landed, you don’t find any people around here any more.
“There’s a couple of hundred years where we don’t find good evidence for people around here. There’s kind of a blip in the radiocarbon dates, whether people were here or not. It’s rare.”
Peck described the Bow Valley as a middle ground between established Aboriginal groups on both the western and eastern edges of the Rocky Mountains. They entered the Bow Valley seasonally, but whether or not people lived here year-round is harder to answer.
“It seems they would come in here seasonally a lot, but it doesn’t seem like we have a record that there was somebody always here, or that this was a place they called home. This was a place they came to more seasonally. I don’t know if that is a fair reflection of the truth or an artifact of the way we’ve done our studies,” he said. “I find it really hard to believe there weren’t people here,” Peck said.
The vast majority – 95 per cent – of archeological work undertaken in Alberta is done in response to development, such as what is occurring at Dead Man’s Flats or in Calgary.
“What’s happening in Calgary? Huge development and we have an amazing amount of information coming out of Calgary – the cultural history, the people, the way they were, what they were doing, we have tons of information about what they were doing because the development is there.”
As a result, Peck said Alberta Culture works closely with developers, not to stop development, but to ensure cultural history is documented and removed or preserved.
“It’s a very, very, very rare day when we say, ‘Absolutely no.’ I can’t think of a single time when we’ve said ‘no.’ It’s more that we’ve said, ‘Slow down, we’ve got to rethink this.’ ”
The fact the bones were found at Dead Man’s Flats tells Julia Lynx of Bison Belong in Banff National Park that Parks Canada is on the right track with its bison restoration project.
“It’s another great sign that … Parks Canada is on the right track and that we want to be supportive to the vision Parks Canada has and help ensure this happens,” Lynx said. “When you’ve got bones unearthed right close to where they’re intending for bison to return, it is just great confirmation that they’re on the right track. I think also it speaks of the integrity of the people working in the area that they reported the finding and that is really important.”
Lynx added the Dead Man’s Flats bison bones help affirm the idea that bison belong in the Rocky Mountains.
“Layer by layer that is becoming true. It takes time for these things to happen and we really appreciate everybody’s continued energy to support Parks in this direction,” Lynx said.
The femur, which is now part of the collection of RAM, will eventually come back to the Bow Valley to be displayed at the Biosphere Institute of the Bow Valley.