﻿1861.] 



HECTOR ROCKY MOUNTAIN'S, ETC. 



441 



to the valley of the North Saskatchewan its average direction is 

 S.S.E., and between that valley and the Athabasca it is S.E. nearly, 

 while to the north of that it is changed to within two points of east 

 and west. These changes in the direction of the strata take place at 

 the different great valleys by which these rivers leave the mountains, 

 and which probably mark the lines of transverse fracture. The 

 mountains are divided into groups by great longitudinal valleys, 

 which are met with in every part of the chain that I examined, 

 running in the length of the range and forming a part of each of 

 the river-systems. The course of these rivers is, therefore, in every 

 case zigzag, alternately flowing through wide valleys either to the 

 north or south, and then making short breaks to the east or west 

 through narrow and rugged defiles. 



Throughout these great valleys it seems to be the arrangement of 

 the detrital deposits that has in many cases determined the direc- 

 tion in which the rivers flow. 



A curious feature is to be remarked in the position of the water- 

 shed between the waters of the Pacific and those of the Atlantic, 

 arising, no doubt, from this cause. It is found gradually to occupy a 

 position further to the west, and through the chain, so to speak, as 

 the rivers rise more to the north. 



Thus the Missouri can hardly be said to rise within the Rocky 

 Mountains at all. Belly River, on the boundary-line, rises from the 

 first ridge before reaching the first longitudinal valley. Kana- 

 niskis River rises in that valley, or from the second range ; Bow 

 River from the third range ; the North Saskatchewan from the 

 fourth range ; the Athabasca from the fifth ; and, although I have 

 not seen Peace River, the one further to the north, still this feature 

 is so well marked that it has been spoken of as rising on the west 

 side of the Rocky Mountains and then cutting through that range 

 to the east. This all tends to show that we must not look on the 

 Rocky Mountains as a continuous range, stretching as a line of frac- 

 ture through the length of the continent, but rather as a succession 

 of centres of disturbance, a fact which has been amply proved within 

 the American territory. 



Thus what are known as the Rocky Mountains at the head of the 

 Missouri are rounded off to the north and south, losing their charac- 

 ter of a lengthened range in that of a mass of mountain- country. 



In like manner the Rocky Mountains within the British territory 

 must be looked upon as a mass with its longer axis lying N.N.W. 

 and S.S.E., with which the main strike of the strata conforms. 



Geological Structure. — There are three of these great longitudinal 

 valleys that are more persistent than the others, each of which marks 

 a change in the formations which compose the mountains. As far 

 west as the first of these, the structure of the mountains may be 

 understood from the sections*, figs. 11 & 12. The strata are of thick- 

 bedded limestones. These limestones are of dark and light-blue 



* All these sections are merely diagrams combining the results of detached 

 observations. 



