|At the confluence of the Bow & Elbow rivers, 11,000 years ago
|Reconstruction of the confluence of the Bow and Elbow Rivers (Calgary, Alberta) 11,000 years ago -- when mammoths, camels, and long-legged horses roamed among the earliest humans to reach the area.||It's a warm autumn day -- a good
day for hunting -- in the Indian summer of 11,000 years ago.
The first snow has come and gone. The vast herds of giant bison are moving westward to the shelter and winter forage of the foothills. All summer long these herds have pastured along the glacial front 250 km to the northeast.
Already the people who have followed the herds all summer across the plains and back again have split into smaller groups and returned to their winter campgrounds along sheltered, south facing slopes of the Kananaskis area.
Here, in addition to bison, they will have deer, caribou, elk, sheep and rabbits to hunt. They will also have plentiful supplies of berries and other wild plant foods to supplement their diet, and abundant firewood for the winter months. Some groups have travelled even further up the mountain to the land of the giant mountain sheep near Banff.
But the young men are restless. Back at the edge of the plains there is still a chance for the more choice prey of mammoth, or even camel, or the sport of spearing small, swift, long-limbed horses.
A small group of hunters has left their camp on the Sibbald Flat to follow the wide Elbow River eastward till it meets the Bow. The hunters carry throwing spears tipped with distinctively fluted points which they have fashioned from quartzite and siltstone cobbles collected from the riverbeds.
From the area know to Calgarians as Scotchman's Hill, the young hunters look across a great braided channel -- more than three kilometres wide -- which stretches from Mount Royal in the south to the hillside below SAIT in the north.
In the spring, this channel contained a frigid, impassable torrent, carrying a load of cobblestones and boulders measuring up to 30 cm in diameter. But now, in the autumn, long gravel bars and a few vegetated islands are exposed. The river which meanders between them can be easily forded.
This wide, gravel channel -- which covers the whole area supporting downtown Calgary today -- is the watering place for all the large mammals of the plains and parklands.
Here the enormous reddish-brown woolly mammoths, with shoulders four metres above the ground and great outward-curving tusks nearly five metres long, come to bathe with their young, and to browse off the willows and poplars which form a thick brush along the river banks and on the islands.
Here, too, come small herds of the North American camel, Camelops, after many days of waterless trekking across the plains. With their long legs and splayed hooves, they are awkward in manoeuvring down the silty banks to the river channel.
Like their Old World counterparts, the dromedary camels, they will drink vast quantities of water before heading back to drier and more open terrain. With winter approaching, their coats have begun to grow long and shaggy.
In much larger herds, small horses of the species Equus conversidens, come to drink from the river. But already these horses are declining -- possibly because of disease or competition for grazing from the cud-chewing bison.
Along with the mammoths and camels which share their watering place at the confluence of the Bow and Elbow rivers, they will soon disappear from southern Alberta and the rest of the North American continent.
Indeed, of all the large mammals at this spot 11,000 years ago, only the bison -- and the humans -- will survive.
But already by this time, the general pattern of human settlement which will characterize the Calgary area until a mere 10 years ago, has been essentially established.
Fantastic as it may seem, very little of this scene is pure conjecture. Rather, this picture has been developed from the carefully documented information provided by a handful of geologists, archaeologists and palaeontologists within the past 20 years.
Some of the information used to develop this reconstruction has been known since the late 1960s, when Dr. C. S. (Rufus) Churcher identified and described bones of large herbivorous mammals which were found in the gravel deposits well above the present Bow River, near Cochrane.
Churcher is an internationally known vertebrate palaeontologist from the Royal Ontario Museum and the department of zoology at the University of Toronto.(1)
By comparing complete and fragmented fossilized bones recovered from these deposits with those of related modern mammals, he has been able to provide us with an idea of the external appearance of most of the now-extinct mammals which once roamed southern Alberta.
But most of our information on the landscape and animals which then characterized the area where the Bow and Elbow rivers meet comes directly from within the city limits. Nearly all this information has been recovered within the past 10 years(2), and most of it is available through the interdisciplinary studies conducted by Dr. Michael C. Wilson of the department of geology and geophysics at the University of Calgary.(3)
Wilson is a Calgarian who has had an insatiable interest since boyhood in all facets of the geology and prehistory of Calgary.
By carefully mapping out the most likely places to look for fossil bone and by continuously monitoring gravel pits and construction sites, he has been responsible for identifying and interpreting the majority of the fossil bones and archaeological sites discovered in Calgary.
One of his most significant "predicted" finds was uncovered during excavation for the building which is now Mount Royal Village.
Even more significant information for our reconstruction -- indeed all reliable information on human occupation of this area as far back as 11,000 years ago -- is provided by two very recently discovered archaeological sites.
One of these sites is at Sibbald Creek in the Kananaskis area; the other is near Vermilion Lakes in Banff National park. Both sites were discovered as the result of Heritage Resources Impact Assessment Studies carried out in advance of highway construction during 1979 and 1983.
The archaeological studies and faunal analyses conducted at the Sibbald Creek site by contract archaeologist Eugene M. Gryba of Calgary and his assistant, Donald A. Barnett, provide us with particularly valuable insights into the lives of the people who occupied this area as early as 11,000 years ago.
Until five years ago, scientists believed that the climate in the Calgary area would have been extremely cold because of the proximity of two great icesheets.
During the Pleistocene era, one of these icesheets had formed by the joining of valley glaciers from the Rocky Mountains, while the other moved southward and westward from the Canadian Shield. These icesheets had converged -- and at times met -- in the Calgary area.
Now, however, Dr. Lionel E. Jackson, a Pleistocene geologist with the Geological Survey of Canada, has found clear evidence that the Rocky Mountain foothills have been free of glacial ice for at least 18,000 years. This evidence came from radio-carbon dates obtained from a bog overlying the highest glacial deposits in the Turner Valley area.
Additional geological evidence indicates that by 11,000 years ago, the Rocky Mountain glaciers had retreated to approximately their present positions.
Even more information on climatic conditions of that period was provided three years ago by sub-fossil pollen recovered from a bog in the Morley Flats. These pollen assemblages, analysed by Glen M. Macdonald (formerly of the department of geography at the University of Calgary), showed that sagebrush and prairie grasses were considerably more abundant in this area than they are today.
Poplar trees, willows and junipers were also abundant, while pine and spruce trees were relatively scarce. Birches and Douglas firs -- which today characterize some of Calgary's natural areas -- were absent.
From this pattern of vegetation we are able to deduce that the climate in this area was somewhat drier than today, and must have been at least as warm.
And so by piecing together the clues provided by bones and hand-worked stones [preserved in the Calgary area -- and by looking at the rocks and landforms and microscopic pollen grains found in peats and sediments -- we are able to develop a detailed picture of life at the confluence of the Bow and Elbow rivers 11,000 years ago.
This is the furthest we can look back in time and see human habitation in what is now Calgary. Tomorrow a new discovery might provide us with an equally clear vision of people who may have occupied this area at an even earlier date.
Find of fossilized bone or hand-worked stone tools should be reported to the Archeological Survey of Alberta in Edmonton (453 9147(4)).
This number may be reached toll-free through the government of Alberta RITE system. To obtain the RITE number for your area, consult your local telephone directory.
© M.L.Richardson, 1984, 1999