On September 1, 1905, the District of Keewatin became one of four districts in the Northwest Territories, the other three being the District of Ungava, the District of Mackenzie, and the District of Franklin. Keewatin covered the portion of the Northwest Territories north and east of Manitoba on the mainland (essentially much of present-day mainland Nunavut, northern Manitoba and northwestern Ontario), and western islands within Hudson and James Bays. After the boundaries of Ontario and Manitoba were extended northward in 1912, Keewatin largely consisted of treeless lands in the Arctic.