The Northwest Territories (NWT; French, les Territoires du Nord-Ouest, TNO) is one of three federal territories of Canada. The Northwest Territories entered the Canadian Confederation July 15, 1870, but the current borders were formed April 1, 1999, with the creation of Nunavut.
While neighbouring Nunavut is mostly Arctic tundra, the Northwest Territories has a slightly warmer climate and is mostly boreal forest (taiga), although about half of the territory is north of the tree line.
The present-day territory was created in June 1870, when the Hudson's Bay Company transferred Rupert's Land and North-Western Territory to the government of Canada. This immense region comprised all of non-confederation Canada except British Columbia, the coast of the Great Lakes, the Saint Lawrence River valley and the southern third of Quebec, the Maritimes, Newfoundland, and the Labrador coast. It also excluded the Arctic Islands except the southern half of Baffin Island; these remained under direct British claim until 1880.
After the transfer, the territories were gradually whittled away. The province of Manitoba was created on July 15, 1870, a tiny square around Winnipeg, and then enlarged in 1881 to a rectangular region composing the modern province's south. By the time British Columbia joined Confederation on July 20, 1871, it had already (1866) been granted the portion of North-Western Territory south of 60 degrees north and west of 120 degrees west, an area that had comprised most of the Stickeen Territories. In 1882, Regina in the District of Assiniboia became the territorial capital; after Alberta and Saskatchewan became provinces in 1905, Regina became the provincial capital of Saskatchewan.
In 1876, the District of Keewatin, at the centre of the territory, was separated from it. In 1882 and again in 1896, the remaining portion was divided into the following districts (corresponding to the following modern-day areas):
Keewatin was returned to the Northwest Territories in 1905.
In the meantime, the Province of Ontario was enlarged northwestward in 1882. Quebec was also extended northwards in 1898, and the Yukon was made a separate territory in that same year in order to deal with the Klondike Gold Rush, and also to remove the NWT's government from the burden of administering the sudden boom of population, economic activity, and the influx of non-Canadians.
The provinces of Alberta and Saskatchewan were created in 1905, and Manitoba, Ontario, and Quebec acquired the last of their modern territories from the NWT in 1912. This left only the districts of Mackenzie, Franklin (which absorbed the remnants of Ungava in 1920), and Keewatin. In 1925, the boundaries of the NWT were extended all the way to the North Pole on the sector principle, vastly expanding its territory onto the northern ice cap. The reduced Northwest Territories was not represented in the Canadian House of Commons from 1907 until 1947, when the electoral district of Yukon—Mackenzie River was created. This riding only included the District of Mackenzie. The rest of the Northwest Territories had no representation in the House of Commons until 1962, when the Northwest Territories electoral district was created in recognition of the Inuit having been given the right to vote in 1953.
In 1912, the Parliament of Canada made the official name of these territories the 'Northwest Territories', dropping all hyphenated forms of it. Between 1925 and 1999, the Northwest Territories covered a land area of – larger than that of India.
On April 1, 1999, the eastern three-fifths of the Northwest Territories (including all of the District of Keewatin and much of that of Mackenzie and Franklin) became a separate Canadian territory named 'Nunavut'.