YUKON TERRITORY  , the most westerly of the northern territories of Canada, bounded S. by British Columbia, W. by Alaska, N. by the Arctic Ocean and E. by the watershed of Mackenzie river . It has an area of 207,076 sq . M . The territory is chiefly drained by the Yukon river and its tributaries, though at the S.E. corner the headwaters of the Liard river, flowing into the Mackenzie, occupy a part of its area . The margins of the territory are mountainous, including part of the St Elias William Healey Dail (1845— ), American naturalist, was born in Boston, Massachusetts, served with the United States Coast Survey of Alaska from 1871 to 1884, became honorary curator of the United States National Museum in 188o,and in 1893 was appointed professor of invertebrate palaeontology at the Wagner Institute of Science, Philadelphia . He was palaeontologist to the United States Geological Survey in 1884–1909 . The white mountain sheep, or Dall's sheep (Ovis dalli), discovered in 1884, was named in his honour . range with the highest mountains in Canada at the S.W. corner (Mount Logan and Mount St Elias), and the N. extension of the Rocky Mountains along the S. and N.E. sides; here, however, not very lofty . The interior of the territory is high toward the S.E. and sinks toward the N.W., and may be described.as a much-dissected peneplain with low mountains to the S . The most important feature of the hydrography is the Yukon (q.v.) and the rivers which flow into it . The Klondike gold mines are reached by river boats, either coming up from St Michael at its mouth, or down 46o m. from White Horse . The White Horse route is now used almost entirely, since the White Pass railway, 111 m. long, was constructed from Skagway, on Lynn Canal, an inlet of the Pacific .

As the voyage up the Pacific coast from

Vancouver or Victoria is almost entirely through sheltered waters, the journey to the Klondike is very attractive in summer . Comparatively little snow is seen in crossing White Pass during summer, though there are patches on the low mountains on each side . The Rocky Mountains, N.E. of the interior 'plateau, are somewhat snowy, but apparently with no large glaciers; but the St Elias range to the S.W. is buried under immense snowfields, from which great glaciers project into the valleys . The rocks are largely ancient schists and eruptives, Palaeozoic or Archean, but considerable areas are covered with Mesozoic and Tertiary rocks, some of which include important seams of lignite or coal, the latter especially in the neighbourhood of White Horse . There have been comparatively recent volcanic eruptions in the region, as shown by a layer of white ash just beneath the soil for many miles along the river, and by a quite perfect cone with a crater and lava stream; but there are no records of volcanic outbreaks within the short modern history of the territory . Before the discovery of gold on the Forty Mile and other rivers flowing into the Yukon the region was inhabited only by a few Indians, but the sensational finds of rich placers in the Klondike (q.v.) in 1896 brought in a vigorous population centred in the mines and at Dawson City, which was made the capital of the newly constituted Yukon Territory . When the White Pass railway was built, White Horse at its N. terminus became of importance, and since then a fluctuating body of prospectors and miners has been at work, not only in the Klondike but at various points along the other rivers . The territory is ruled by a governor and council, partly elective, seated at Dawson, and has a representative in the parliament of the Dominion . Almost the only economic product of the territory was at first gold, but copper and other ores later began to attract attention in the S. near White Horse . Though so near the Pacific the Yukon territory has a rigorous continental climate with very cold winters seven months long, and delightful sunny summers . Owing to the lofty mountains to the W. the amount of rain and-snow is rather small, and the line of perpetual snow is more than 4000 ft. above sea-level, so that glaciers are found only on the higher mountains; but the moss-covered ground is often perpetually frozen to a depth of loo or 200 ft . Vegetation is luxuriant along the river valleys, where fine forests of spruce and poplar are found, and the hardier grains and vegetables are cultivated with success .

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