British Columbia, the western province of the Dominion of Canada. It is bounded on the east by the continental watershed in the Rocky Mountains, until this, in its north-westerly course, intersects 120° W., which is followed north to 60° N., thus including within the province a part of the Peace river country to the east of the mountains. The southern boundary is formed by 49° N. and the strait separating Vancouver Island from the state of Washington. The northern boundary is 60° N., the western the Pacific Ocean, upon which the province fronts for about 600 m., and the coast strip of Alaska for a further distance of 400 m. Vancouver Island and the Queen Charlotte Islands, as well as the smaller islands lying off the western coast of Canada, belong to the province of British Columbia.
British Columbia is essentially a mountainous country, for the Rocky Mountains which in the United States lie to the east of the Great Basin, on running to the north bear toward the west and approach the ranges which border the Pacific coast. Thus British Columbia comprises practically the entire width of what has been termed the Cordillera or Cordilleran belt of North America, between the parallels of latitude above indicated. There are two ruling mountain systems in this belt - the Rocky Mountains proper on the north-east side, and the Coast Range on the south-west or Pacific side. Between these are subordinate ranges to which various local names have been given, as well as the "Interior Plateau" - an elevated tract of hilly country, the hill summits having an accordant altitude, which lies to the east of the Coast Range. The several ranges, having been produced by successive foldings of the earth's crust in a direction parallel to the border of the Pacific Ocean, have a common trend which is south-east and north-west. Vancouver Island and the Queen Charlotte Islands are remnants of still another mountain range, which runs parallel to the coast but is now almost entirely submerged beneath the waters of the Pacific. The province might be said to consist of a series of parallel mountain ranges with long narrow valleys lying between them.
The Rocky Mountains are composed chiefly of palaeozoic sediments ranging in age from the Cambrian to the Carboniferous, with subordinate infolded areas of Cretaceous which hold coal. The average height of the range along the United States boundary is 8000 ft., but the range culminates between the latitudes of 51° and 53°, the highest peak in the Canadian Rockies being Mount Robson, 13,700 ft., although the highest peak in British Columbia is Mount Fairweather on the International Boundary, which rises to 15,287 ft. Other high peaks in the Rocky Mountains of Canada are Columbia, 12,740 ft.; Forbes, 12,075; Assiniboine, 11,860; Bryce. 11,686; Temple, 11,626; Lyell, 11,463. There are a number of passes over the Rocky Mountains, among which may be mentioned, beginning from the south, the South Kootenay or Boundary Pass, 7100 ft.; the Crow's Nest Pass, 5500 (this is traversed by the southern branch of the Canadian Pacific railway and crosses great coal fields); the Kicking Horse or Wapta Pass, 5300 (which is traversed by the main line of the Canadian Pacific railway); the Athabasca Pass, 6025; the Yellow Head Pass, 3733 (which will probably be used by the Grand Trunk Pacific railway); the Pine River Pass, 2850; and the Peace River Pass, 2000, through which the Peace river flows.
The Coast Range, sometimes called the Cascade Range, borders the Pacific coast for 900 m. and gives to it its remarkable character. To its partially submerged transverse valleys are due the excellent harbours on the coast, the deep sounds and inlets which penetrate far inland at many points, as well as the profound and gloomy fjords and the stupendous precipices which render the coast line an exaggerated reproduction of that of Norway. The coast is, in fact, one of the most remarkable in the world, measuring with all its indentations 7000 m. in the aggregate, and being fringed with an archipelago of innumerable islands, of which Vancouver Island and the Queen Charlotte Islands are the largest.
Along the south-western side of the Rocky Mountains is a very remarkable valley of considerable geological antiquity, in which some seven of the great rivers of the Pacific slope, among them the Kootenay, Columbia, Fraser and Finlay, flow for portions of their upper courses. This valley, which is from 1 to 6 m. in width, can be traced continuously for a length of at least 800 m. One of the most important rivers of the province is the Fraser, which, rising in the Rocky Mountains, flows for a long distance to the north-west, and then turning south eventually crosses the Coast Range by a deep canton-like valley and empties into the Strait of Georgia, a few miles south of the city of Vancouver. The Columbia, which rises farther south in the same range, flows north for about 150 m., crossing the main line of the Canadian Pacific railway at Donald, and then bending abruptly back upon its former course, flows south, recrossing the Canadian Pacific railway at Revelstoke, and on through the Arrow Lakes in the Kootenay country into the United States, emptying into the Pacific Ocean at Astoria in the state of Oregon. These lakes, as well as the other large lakes in southern British Columbia, remain open throughout the winter.
In the north-western part of the province the Skeena flows south-west into the Pacific, and still farther to the north the Stikine rises in British Columbia, but before entering the Pacific crosses the coast strip of Alaska. The Liard, rising in the same district, flows east and falls into the Mackenzie, which empties into the Arctic Ocean. The headwaters of the Yukon are also situated in the northern part of the province. All these rivers are swift and are frequently interrupted by rapids, so that, as means of communication for commercial purposes, they are of indifferent value. Wherever lines of railway are constructed, they lose whatever importance they may have held in this respect previously.
At an early stage in the Glacial period British Columbia was covered by the Cordilleran glacier, which moved south-eastwards and north-westwards, in correspondence with the ruling features of the country, from a gathering-ground situated in the vicinity of the 57th parallel. Ice from this glacier poured through passes in the coast ranges, and to a lesser extent debouched upon the edge of the great plains, beyond the Rocky Mountain range. The great valley between the coast ranges and Vancouver Island was also occupied by a glacier that moved in both directions from a central point in the vicinity of Valdez Island. The effects of this glacial action and of the long periods of erosion preceding it and of other physiographic changes connected with its passing away, have most important bearings on the distribution and character of the gold-bearing alluviums of the province.