Alaska (and perhaps part of northwestern Canada) is the homeland of Athapaskan-speaking peoples in the New World. Prehistoric migrations explain their presence in other areas. Although it is difficult to associate specific Athapaskan peoples with particular prehistoric archaeological traditions, it seems reasonable to suggest an Athapaskan presence in Slavey territory since about 50 B.C. —that is, through the encompassing Mackenzie, Spence River, and Fort Liard complexes. The Slavey would have had relatively few contacts with non-Athapaskan-speaking peoples. First contact with Europeans occurred in June and July of 1789, when Slavey encountered Alexander Mackenzie during his exploration of what would become the Northwest Territories. For the next 125 years knowledge of and contact with the West came Primarily through fur traders and Roman Catholic and Anglican missionaries. Between the late 1790s and 1858 a number of trading forts were established in Slavey territory. Between 1900 and 1922 two treaties were signed with the Canadian government. In the 1930s mineral resources were discovered in Slavey territory and have subsequently been developed. Since the 1960s, Canadian government programs have had a great impact on Slavey culture and society. Culturally, Slavey are most closely related to other Dene (Athapaskan Indians) in northwestern Canada—Dogrib, Bearlake, Mountain, and Hare peoples. They are also culturally similar to the Athapaskan-speaking Chipewyan, Beaver, and Kaska Indians from northern Alberta and northern British Columbia.