6000 B.C. - 4000 BC
Between 6000 and 4000 BC the general warming trend began to effect Northern Manitoba. The glaciers retreated and Lake Agassiz contracted. Spruce forests expanded over the landscape advancing the tree line to at least 300 km beyond its present-day location. Big game animals, particularly the caribou, migrated to take advantage of the new food sources and Native hunters using Plano tools followed.
The first northern peopes, referred to as Northern Plano, possibly arrived in northern Manitoba via the plains of Saskatchewan which were ice free about 8500 years ago ( Meyer 1983). The Northern Plano people were probably an off-shoot of the Western Plano who followed the long horned Bison to their northern limits and then gradually turned to hunting barren-ground caribou (Rangifer tarandus). They may have skirted the northern shores of Lake Agassiz, moving seasonally with the herds. This change in subsistence base from bison to caribou distinguishes Northern Plano from contemporary cultures in southern Manitoba and is most evident in the characteristics of the projectile points.
Archaeological evidence of Northern Plano traditions is limited to single artifact finds. They are located at strategic water body crossings and indicate a hunting strategy which focused on intercepting and slaughtering large numbers of animals in much the same manner as the early bison hunters to the south. The earliest occupations contain the least amount of cultural material and are the poorest understood. The most prolific cultural material identified in this area is considered to be a late expression of the Agate Basin component of the Late Sister Hills Complex (Dyck 1983) predominant in southern Manitoba. However, not enough research has been conducted to establish a firm continuity.
Agate Basin points of the Northern Plano tradition are described as "...biconvex quartzite lanceolates with tapered ground stemmed bases." (Gordon 1996:237). Local quartzite cobbles from the glacial deposits provided stone for tools. Gordon ( 1996) has further divided the Northern Plano tools into two groups, the tundra and forest (Gordon 1976). Tundra tools are marked with a high degree of burination along their sides, involving considerable reworking of lanceolate points for re-use that is not apparent in the forest sites. The variation between these forms is related to the lack of suitable stone in the tundra zone and suggests that the hunters travelled between these two regions in response to the annual caribou migration, intensively retouching their tools when they were away from their raw materials.
Wright (1995) has noted that although the lanceolate points of Western Plano and Northern Plano are similar, other tools are quite different. Northern Plano tools include chipped and polished stone adzes, chithos, wedges, saws, linear flakes, gravers-on-a-point, and scraper-knives, which are absent from early Western Plano culture. Harp (1961), Wright (1976) and Gordon (1996) have observed that broken tools were re-used as burins. The distinct Northern variants may reflect the change of subsistence base from bison to caribou. In addition, the use of heated rocks in food preparation evident in Northern Plano, is not present in the archaeological record of Western or Eastern Plano, except for the Caribou Lake Complex.
Nash (1975) notes that Northern Plano sites were located near the present-day water levels and drainage patterns, suggesting that people inhabited this area only after stabilization of the environment. The majority of Northern Plano sites were located at possible caribou crossings and along esker systems (long, high ridges of glacial debris) where a cooperative interception strategy could be effectively pursued. Gordon (1996) has proposed a discrete band/discrete herd hypothesis, which maintains that each band developed a special permanent relationship with a specific caribou herd. Groups would have accordingly followed separate migration routes and developed local cultural differences. His suggestion is consistent with patterns of historic caribou/reindeer exploitation.