November 2010 - BC Hydro

Duncan Dam Reservoir Archaeological Overview Assessment Final Report
the adoption of the atlatl (or spear thrower) and different hunting methods. If these components
represent later use (as their landform setting suggests), this change in hunting technology may
reflect human adaptation to the changing early Holocene ecology, but at present there is too
little data available to formally evaluate such an hypothesis.
The relatively abundant evidence of early postglacial human inhabitation of the Purcell Trench
vicinity is a noteworthy feature of the archaeology of British Columbia. In contrast, there is very
little controlled data from the West Kootenay area for the time period between about 8000 and
5000 years ago. This is reflected in a virtual hiatus at the Kettle Falls fishery during the
Slawntehus Period (Chance and Chance 1985). The present evidence from the study area
consists of surface finds of large side-notched and side/corner-notched points similar to those
dating to this time in adjacent regions. While the sparseness of data may reflect less intensive
human use of the area (the data from Kettle Falls indicate a collapse of the early Holocene
fishery), it could also be the result of the very limited systematic archaeological investigation in
the region, especially in upland settings. The focus of survey and excavation on pithouses on
low elevation terraces may be responsible for the dearth of documented evidence, as
occupation may have been in open camps on high terraces whose deposits were not
extensively sampled. It is apparent that the Rocky Mountains to the east supported significant
human populations during this time.
Climatic conditions apparently became moister within the last 6000 years, especially after 5000
BP as global cooling increased the influence of the Maritime Westerlies when the mean position
of the storm track shifted southwards. In archaeological sites around Creston BC, in northern
Idaho, and as far up the Kootenay River as the Libby, Montana vicinity, the distinctive siliceous
metasiltite known as Kootenay Argillite is abundantly represented. The source of this stone is
just south of the present study area, indicating that the north arm of Kootenay Lake was an
especially important part of the aboriginal seasonal round between about 5000 and 2500 years
ago when Kootenay Argillite attained its highest proportions in upriver artifact assemblages. In
other parts of the region, this time period is characterized by a greater orientation to the
resources of aquatic and riparian habitats by the resident human populations. It has also been
hypothesized that salmon-carrying capacity reached its maximum during this time period
(Choquette 1985). The Inissimi Complex was defined for the 5000 - 2500 BP time period to
encompass a distinctive set of artifact assemblages on the Kootenay River and its major
tributaries, from the big bend in north western Montana downstream at least as far as the north
Eagle Vision Geomatics & Archaeology Ltd. 18 November 28, 2010