TOPOGRAPHY. The physiography of Canada falls broadly into three great divisions. distin guished by fundamental differences in geological structure, surface, and climate, namely: 1. The hilly, diversified eastern half. II. The elevated interior plains, comparatively level. and largely treeless, sloping gently northeast and north. III. The mountain region. between the plains and the Pacific Coast, or the Alaskan region, which con sists of the northern extension of the Rocky 3Iountains of the United States, their included plateaus, and of various coast ranges. Each of these prime features of the continental topog graphy is divisible into certain large. natural subdivisions, which conform in the main to the drainage basins, determined by the events of geo logical history.
1. The eastern part of Canada has a broken or hilly surface of generally low elevation. The highest points of the coast of Labrador approach 5000 feet, but the interior of northern Quebec and of Labrador, or of the region west of Hudson Bay. does not exceed 1500 to 3000 feet, and slopes steadily to the level of the shores of Hudson Bay. This whole vast region. embracing the land from the lower Saint. Lawrence to Hudson Bay, and continuing in a broad margin around it, is a succession of low, often bare or thinly forested ridges of hard rocks, between which are inntuner able lakes, swamps (inuskegs'), and torrential rivers. Its recent release from universal glacia tion, and the unfavorable elimate, have not per mitted 11111011 valuable soil to aecumulate, except in small, isolated areas, and the region is not adapted to any considerable human habitation. Alany large rivers flow into Hudson Bay from the some shorter, but copious ones, from the south of which the \loos and Abitibbi form canoe routes to James Bay; while the Albany River forms a Caine route from the Lake of the Woods to the same inlet. In the west the drain age into Hudson Bay includes the whole basin 01 the Red, Saskatchewan, Churehill, and other riv ers. this embracing the southern half of the inte rior plains area; but this will be spoken of later. The Hudson Bay basin is defined south and southeast by a scarcely perceptible watershed, called 'the height of land.' or, along the north ern boundary of the Province of Quebec, where it is better defined the 'Laurentian Hills,' which divides the heads of the streams flowing north ward from those draining southward into the Saha Lawrence. This very ancient river valley, which includes the whole system of the Great Lakes (partly within the United States), is over 2000 miles long, and forms the drainage outlet for an area of about 500,000 square miles. The surface of the Saint Lawrence Valley is broken in places by intrusive igneous rocks, which re main standing above the surface in such abrupt heights as Mount Royal, at Montreal. and the picturesque buitys south of that city. Another topographic feature in this region is the Niagara Escarpment. the eastern edge of a plateau over the brink of which the waters of Lake Erie are poured into Niagara Falls (q.v.). As the escarp ment is traced northward. it becomes more lofty, rising into high, rocky hills, which form the backbone of the triangular, very picturesque ex tension of land separating Lake Huron from Georgian Bay. The valley of the Saint Lawrence narrows toward its mouth, where the northeast ern extension of the Appalachians forms the mountainous Gasp Peninsula and also the islands of Antieosti and Newfoundland. South of this lies the distinct region of the Maritime Provinces, whose features are largely similar to those of New England. See NEW BRUNSWICK ; NOVA SCOTIA; PRINCE EDWARD ISLAND.
11. The second great division of Canada—the Interior Plains—comprises the area, some 700 miles in breadth, which continues the plains of the United States northward to the shores of the Aretie Sea, between Hudson Bay and the Rocky Mountains. This region is, however, more brok en, well watered, and has more forest than the high, open plateaus southward, and is lower, constantly diminishing in altitude northward, the international boundary (latitude 49° N.) nearly coinciding with the watershed between the drainage into the Gulf of Mexico and that into Hudson Bay. Referring to this Canadian plains region. George M. Dawson, chief of the Geo logical Survey of Canada, wrote: whole interior region of the continent slopes gradually eastward from the elevated plains lying near the has of the Rocky Moun tains to the foot of the Laurentian Highlands, and, though the inclination is more abrupt in approaching the mountains, it is not so much so as to attract special attention. Between the fifty-fourth and forty-ninth degrees of latitude. however. along the lines which are in a general way parallel and hold a northwest and southeast course across the plains, very remarkable step like rises occur. These escarpments form the eastern !mond:tries of the two higher prairie pla teaus, and the most eastern of them overlooks the lowest prairie level, or that of the Red River Valley. The three prairie steppes thus outlined differ much in age and character, and have been impressed on the soft formations of the plains by the action of sulefflrial denudation of former great lakes and probably also of the sea. . . . The actual increase of elevation accounted for in the two esea•pments, however, is slight compared with that due to the uniform eastward slope of the plains. The direction of greatest inclina tion is toward the northeast, and a line drawn from the intersection of the fortyninth parallel and the mountains to a point on the first prairie level north of Lake Winnipeg will he found to cross the escarpments nearly at right angles, and to have an average slope of 5.38 feet to the mile.
From the same initial point, in a clue east iine to the lowest part of the valley of the Red Riven a distance of 750 miles, the plains have an average slope of 4.48 feet per mile. . . . Northwest of the North Saskatchewan no ex tensive treeless plains occur in the central region of the continent, and the forest country of the cast forms a wide, unbroken connection with that of the northern portion of British Co lumbia." Along the edge of the lowest or easternmost of these levels lies that series of great lakes— Manitoba, Winnipeg, \Vinnipegoosis, Reindeer, La Bache, and many other lesser ones—which form so striking a feature on the map, and empty by large, rapid rivers into Hudson Bay. Down from takes on the second level flow such large rivers as the English or Churchill, lee and Dobaunt, the lee carrying to Hudson Bay some overflow from Lake Athabasca; while from the foot of the Rocky Mountains, and gathering the drain age of all three plains levels, comes the great Saskatchewan, in two branches. the North and the South, to enter Lake Winnipeg (which also receives from the south the large Red-Assini. boine affluent). and thenee to flow through Nel son River to Hudson Bay. North of the North Saskatchewan. on about the 55th parallel of north latitude, a line of rocky and forested highlands forms a watershed between its valley and that of the outflow toward the north. This begins with the great Athabasca and Peace ricers, which pass eastward from the base of the Rockies through a rough region to Athabasca Lake, and thence enlarged (as the Slave River) to Great Slave Lake. which also receives the powerful Liam-d from the west. This lake narrows west wardly into the Mackenzie, which flows north westward to the Arctic Ocean, about 120 miles east of the border of Alaska. 'rids great river is the equal of the Missouri in length, but dis charges more water than does that stream, and is comparable to the mighty watercourses of Si beria. Its course lies near the base of the Rocky Mountains, west of which lie the head streams of the Yukon (q.v.). all of which are within Canadian territory. East of the Mackenzie, half way between Great Slave Lake and the Arctic Coast, lies the extensive Great Bear Lake, a feeder for the Mackenzie. Here the country is low, and a part of this lake's waters escapes into Coronation Bay by way of the Coppennime Riv er. East of the head of the Coppermine a low divide turns the waters east of it into the Great Fish or Back River, which blows through the desolate wastes, Called the Barren Grounds, that He between Hudson Bay and the Arctic Ocean (Victoria Strait), and empties into the latter at Elliot Bay. Of all these rivers. the greatest is the Mackenzie, but the most important are the Saskatchewan and the Red, for they have made available a wide area of habitable and valuable land. The Saskatchewan collects most of the waters of the three districts, Alberta. Assini Wine, and Saskatchewan. by the two main chan nels, each some 300 miles in length. and then flows 200 miles more to Lake Winnipeg. This lake also receives, besides the lied River and its tributary, the Assiniboine ( which drain all smith ern Manitoba and mueh of North Dakota and :Minnesota). the Winnipeg River. and the lakes Manitoba, Dauphin, and Winnipegoosis, which, to gether. equal or exceed the bulk of Lake Erie. Lake Winnipeg itself is nearly as spacious as Lake Huron, and pours its waters through the great Nelson River. a series of rapids descending to Hudson Bay, The Saskatchewan and Red riv ers were the former avenues of travel, and their valleys are now the seat of the principal popula tion and industry in the Northwest.
Ill. The mountainous western border of Cana da consists of a belt of snowy ranges from 500 to 600 miles in width. On the east are the Rocky Mountains, continuous with those of 3Ion tana, which consist of gigantic uplifts and fold ings of the strata. Hence the scenery presents series of vast bedded cliffs, and weather-worn, jvged summits, instead of the rounded domes and slopes familiar in the southern Roekies. The ranges run northwest in approximately parallel lines, which are capped with snow and glaciers. This is due to their high latitude rather than to altitude, since there are but few peaks that ex ceed 11,000 feet. except between latitudes 511° and 53°, where a number of peaks have recently been described whose elevations appear to exceed 13, 000 and 14.000 feet. Mounts Columbia, Forbes, Bryce. Alberta, and Freshfield arc seemingly the highest of these. A somewhat distinctive range west of the first is the Selkirk. in which are the headwaters of the Columbia River. and which carries the Great or Illecilleweat glacier. Then conies the Gold or Columbia Range, while farther west lies a broad, elevated plateau valley, drained by the Thompson and Fraser rivers, and forming the centre of British Columbia. Between this valley and the Pacific Coast extends a belt of intricate coast ranges, which northward form the boundary mountains between Canada and Alaska. and whose outermost summits consti tute the line of islands—Vancouver, Queen Char lotte. and the Alexander Archipelago— which characterize that coast. (See BRITISH CO1.1711 ma and ArAsKA.) It is through these coast ranges that the Fraser River (about equal to the Ohio) cuts its way in a series of magnificent callous. These orographie features have had a eery important bearing on both the climate and the economic value of this part of the country.