Right, the culture history of the Eastern Slopes of west-central Alberta is divided into three periods based on technological changes in projectile points.
During the last Ice Age the glaciers in west-central Alberta reached their maximum extent about 20,000 years ago, forming a barrier along the Eastern Slopes of the Rocky Mountain foothills south into Montana. After the glaciers retreated, plants re-colonized the valley floors and alpine areas 11,000–10,000 years ago, creating a generally hospitable environment for human occupation.
The Early Precontact Period (10,500–7,750 years ago) is characterized by archaeological complexes containing stone projectile points of triangular, fluted, lanceolate, or stemmed forms, presumably used with throwing and stabbing spears. At least five cultural complexes occur in Alberta, including Clovis and its derivatives, Windust, Cascade, Cody, and Plains-Mountain. These groups appear to have been primarily big-game hunters who often moved over vast areas during their annual rounds while visiting preferred resources. Their stone tools can be found great distances from the sources of their raw material.
The Middle Precontact Period (7,750–1,600 years ago) began with the appearance of side- and corner-notched dart points used to tip spears launched by an atlatl, or throwing stick. This period encompasses both the warm, dry mid-Holocene climatic interval and the initial return to cool-wet conditions during the late Holocene. The transition between these climates resulted in the expansion and closing of forests, the development of extensive tracts of muskeg (bogs) on former meadowland, and the lowering of the tree lines on the alpine slopes. A number of archaeological complexes and phases are present, including the Mummy Cave Complex, its derivative Oxbow, and the McKean Complex. These groups made more intensive use of local resources than their predecessors, and their toolkits indicate a greater focus on medium-sized mammals, plants, and the processing/cooking of these food supplies using stone boiling and hot-rock roasting techniques, particularly toward the end of the period. During the later part of the Middle Precontact Period, the cultural sequence diverges between the north and south, correlating with the appearance of boreal forests in the north. New complexes include the Pelican Lake Phase, Besant Phase, Shuswap Horizon, and the Taltheilei Tradition.
The Late Precontact Period (1,600–200 years ago) is characterized by the appearance of the bow and arrow, represented in the archaeological record by small notched arrow points. Pottery also appears in some of the later archaeological complexes. Archaeological phases include the Avonlea, Old Women’s, Tobacco Plains, Mortlach, Kamloops, and Taltheilei, apparently representing Blackfoot, K’tunaxa, Assiniboine, Cree, Salish, and Dene speaking peoples. These groups demonstrate diversity in settlement patterns and resource use. In the south, many groups summered on the plains and spent the winter along the foothills, whereas to the north, areas with good fishing lakes became increasingly important.
About 300 years ago we begin to see the impact of the Fur Trade, which resulted in major changes to resource harvesting and occupancy. Eventually, many native peoples were forcibly confined to their reserves after signing treaties, and game populations became depleted through disease and over-hunting. The later removal of lands and reserves and the massive depopulation caused by such diseases as tuberculosis and influenza forced the abandonment of traditional patterns of seasonal resource harvesting and occupancy along Alberta’s Eastern Slopes.