Migration

The spread of the McKean Complex was quite rapid. The demise was also quite sudden as the number of sites rapidly decreased around 3220 B.P. By 2440 B.P. McKean sites were non- existent on the Plains with sites only being located in the foothills and mountainous areas of the Rocky Mountains. The McKean Complex first appears in the mountainous areas surrounding the Bighorn Basin. Many of the oldest dates are concentrated in the areas of the Absaroka Range, the Big Horn Mountains, and the Black Hills, as well as the surrounding vicinity. Sites are located in a wide range of environments as demonstrated in Chapter 5 outlining the McKean sites in

various ecoregions.

To provide a simple examination of the rates of spread of the McKean Complex we will examine distances and changes in radiocarbon ages from the hypothesized origin of the McKean Complex. The following table outlines these speeds as the based only on the oldest radiocarbon age of each site and the distance between sites as the crown flies. Speed is described in

kilometres per year. These speeds are comparable to the spread of the Neolithic across Europe (0.6 – 1.3 km/year) , the initial colonization of Europe (0.4 km/year) and the spread of Folsom from the Hell Gap Site (1.7 km/year) (Collard et al. 2010; Fort et al. 2004).

Table 7.2 Rate of Movement from Origin Location

There are two processes that archaeologists have identified to explain transition in prehistory, the movement of ideas (cultural diffusion) and the movement of people (demic diffusion). Cultural diffusion is assumed to be faster than demic diffusion because with cultural

Start Location End Location Distance (km) Δ RC age

(years)

Speed (km/year)

Direction from Origin

Rigler Bluff Dipper Gap 795 1520 0.52 SE

Rigler Bluff McKean 450 528 0.85 E

Rigler Bluff Crown Site 1045 710 1.47 NNE

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diffusion learning can occur across and within a generation of people. But recent studies have shown that demic diffusion can be rapid if the population has niche preferences that limit dispersal such as river valleys (Campos et al. 2006). Distinguishing between these two types of diffusion is difficult using the archaeological record especially if there is evidence of a

population that is already in place (Hamilton and Buchanan 2007; Rodrigues-Iturbe et al. 2009). When there is no pre-existing population the process would be demic diffusion (Collard et al. 2010).

Table 7.2 shows a relatively rapid movement northward along the Saskatchewan River region. The McKean Complex was present at the Crown Site before sites such as Cactus Flower, Thundercloud, Cut Arm and Redtail. A McKean occupation did occur at the Dog Child Site before the Crown Site was occupied. This rapid spread northwards is indicated by the speed at which this technology would have travelled. The spread of the McKean complex projectile point technology travelled faster northwards from the origin location than it did to the nearby Black Hills. There appears to be a band of older dates extending from the origin area north to the area surrounding the Crown site. This pathway shows the movement of this technology early into central Saskatchewan.

The speed in which this Complex spread is relatively faster to the north than to the east and the south. This faster rate may demonstrate a cultural diffusion. Peck (2011) suggested that this movement occurred potentially by following a river system and the use of niche ecosystems along a river system and this could be the reason for the quick speed that this Complex reached the Crown Site. The introduction of the McKean Complex in Colorado coincides with the highest number of sites. This movement may be due to population pressures in the Black Hills and the need to move to new areas because of pressures on the resources.

Some researchers (Davis and Keyser 1999; Tratebas 1998) have suggested that the McKean Complex in Canada is best explained by diffusion of points rather than migration due to a lack of grinding stones, differences in faunal assemblages, and lack of slab-lined roasting pits. Grinding stones are evident in Canada at the Redtail site and the Wolf Willow site (Walker 2015, personal communication). The lack of slab-lined roasting pits and fewer grinding stones could possibly be related to the scarcity of slab type rocks in the northern regions of the Northern Plains. Slabs of rocks would be easier to acquire in mountainous environments. In the northern regions, rocks are often till, debris and sediment left behind after the last glaciation. As will be

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seen in section 7.2.1, there is no evidence for differences in faunal assemblages from north to south. While the highest average number of faunal species were found in the Middle Rockies, other areas that have higher than average numbers of faunal remains (by species) include the Aspen Parklands and the Mid-Boreal Lowland and Interlake Plain. Some southern areas such as the West-central Semi-arid Prairies and the Temperate Plains contain the fewest numbers on average.

Support for a migratory population is also evident by the Gray Burial site. This is an Oxbow burial site located near Swift Current, Saskatchewan. This burial site contains hundreds of burials in a cemetery associated with the Oxbow Complex. Walker (personal communication, 2012) has suggested that this is a type of territorial marker, marking the territory of an existing population to a migratory population. Currently, this is the only known cemetery style burial ground on the Northern Plains. The model presented in this research provides one line of evidence to support this theory. If in fact there was a migratory population of the McKean Complex onto the Canadian Northern Plains and the route suggested was used, the Gray Burial Site is located within this pathway The position of this burial ground suggests that it is possible that it was a territorial marker positioned used as a sign for a migratory population. If this is the case this marker did not work as the McKean Complex spread quite quickly into and beyond this region. The differences in mortuary behaviour of Oxbow and McKean also suggest that these are two different populations (Walker 1984).