The Northwest Territories, a portion of the old North-Western Territory, entered the Canadian Confederation on July 15, 1870, but the current borders were formed on April 1, 1999, when the territory was subdivided to create Nunavut to the east, via the Nunavut Act and the Nunavut Land Claims Agreement. While Nunavut is mostly Arctic tundra, the Northwest Territories has a slightly warmer climate and is both boreal forest (taiga), and tundra, and its most northern regions form part of the Canadian Arctic Archipelago.
The name is descriptive, adopted by the British government during the colonial era to indicate where it lay in relation to Rupert's Land. It is shortened from North-Western Territory (see History). In Inuktitut, the Northwest Territories are referred to as ᓄᓇᑦᓯᐊᖅ (Nunatsiaq), "beautiful land."
There was some discussion of changing the name of the Northwest Territories after the splitting off of Nunavut, possibly to a term from an Aboriginal language. One proposal was "Denendeh" (an Athabaskan language word meaning "our land"), as advocated by the former premier Stephen Kakfwi, among others. One of the most popular proposals for a new name – one to name the territory "Bob" – began as a prank, but for a while it was at or near the top in the public-opinion polls.
In the end a poll conducted prior to division showed that strong support remained to keep the name "Northwest Territories". This name arguably became more appropriate following division than it had been when the territories extended far into Canada's north-central and northeastern areas.