2 GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. 



having a total width of about four hundred miles, and the component ranges 

 are straighter and more regular. The S3^stems are progressively higher from 

 the coast eastward, cuhninating in the Rockies proper, which stand as a lofty 

 buttress along the western margin of the great central plains. Between the 

 Coast and the Gold ranges there lies an interior plateau a hundred miles wide 

 with an average elevation of about 3,500 feet above sea-level. The Gold, 

 Selkirk, and Rocky systems are separated by the Columbia and the Columbia- 

 Kootenay valleys, made by the action of water and ice along the strike of the 

 geological formations, assisted probably by some dislocations of the strata. 



The Rocky Mountains, or as formerly called, the Stony Mountains, consist of 

 an imposing array of parallel ranges with a general trend in this region of north- 

 northwest to south-southeast, separated by longitudinal valleys and attaining 

 a total breadth of 40 to 50 miles. Compared with the systems to the west 

 they are strikingly rugged in character and free from vegetation. Skirting the 

 eastern border, and a part of them both geologically and structurally, are the 

 "foot-hills," consisting of folded parallel ridges, reaching out 15 to 20 miles and 

 merging into the "plains" at an elevation of about 3,300 feet. 



b. Streams. — ^The main streams occupy the longitudinal valleys for a 

 portion of then- course, leaving the mountains by the transverse valleys, which 

 extend into the foot-hills. According to Dawson the base-level of the streams 

 upon leaving the mountains to the eastward is about 4,360 feet, while to the 

 west it is about 2,450 feet above sea-level. Upon the eastern slope of the Great 

 Continental Divide the waters are gathered into the Saskatchewan and reach 

 the Atlantic Ocean by way of Hudson Bay; while those to the west drain into 

 the Columbia River and work their way to the Pacific Ocean. As pointed out 

 by Dawson, the actual water parting does not correspond entirely with the 

 highest crest line of the mountains, but lies to the eastward, in which direction 

 it seems to be moving. Between the international boundary of north latitude 

 49° and 52°, the Rock}- Mountains are sharply separated from the Selkirks to 

 the west bj- the Columbia-Kootenay Valle}-, which maintains a considerable 

 breadth and a remarkably straight course through more than three degrees of 

 latitude. This valley is filled with drift materials to a considerable depth and 

 is undergoing but little erosion, the river simply cutting tortuous channels 

 through the loose deposits. The eastern side of the valley is generally steep 

 and escarpment-like, while the western is rounded and wooded. The Columbia 

 starts within a mile and a half of its southward -flowing tributary, the Kootenay, 

 and moves northwestward in a great sweep as though intent upon capturing 

 the drainage of the region before starting for the sea. In this great fold it en- 

 closes and sharply limits the less rugged, but picturesque, Selkirk System, 

 with its subdued outlines and forested slopes. Some of the eastern ranges are 

 continuous and have the same general trend as those of the Rockies, but, in 

 general, there is less regularity and continuity in the arrangement of cres'ts 

 and peaks, and they do not attain as great a height. The drainage is all into 

 the Columbia River, and the streams are unable to develop any considerable 



