Notices of Memoirs — Dr. Dawson — On the Rocky Mountains. 505 



into the Arctic, and of the correspondences of the Cretaceous, Tertiary, 

 and Pleistocene of the Arctic Basin with those of America, and the 

 bearing of these facts on questions of palseogeography. 



III. — On the Rocky Mountains, with special reference to that part 

 of the Range between the 49th Parallel and Head- waters oe 

 the Red Deer River. By George M. Dawson, D.Sc, F.G.S., etc., 

 Assistant-Director, Geological Survey of Canada. 



THE term " Rocky Mountains " is frequently applied in a loose way 

 to the whole mountainous belt which borders the west side of 

 the North American continent. This mountainous belt, is, however, 

 preferably called the Cordillera region, and includes a great number of 

 mountain systems or ranges, which on the 40th parallel have a breadth 

 of not less than 700 miles. Nearly coincident with the 49th parallel, 

 however, a change in the general character of the Cordillera region 

 occurs. It becomes comparatively strict and narrow, and runs to the 

 56th parallel or beyond with an average width of about 400 miles only. 

 This portion of the western mountain region comprises the greater 

 part of the province of British Columbia. It consists of four main 

 ranges, or, more correctly, systems of mountains, each including a 

 number of component ranges. These mountaiu systems are, from east 

 to west: — (1) The Rocky Mountains proper. (2) Mountains which 

 may be classed together as the Gold Ranges. (3) The system of the 

 Coast Ranges of British Columbia, sometimes improperly named the 

 Cascade Ranges. (4) A mountain system which in its unsubmerged 

 portions constitutes Vancouver and the Queen Charlotte Islands. 



The present paper refers to the Rocky Mountains proper. This 

 system, between the 49th and 53rd parallels, has an average width of 

 about 60 miles, which, in the vicinity of the Peace River, on the 56th 

 parallel, decreases to about 40 miles. It is bounded to the east by the 

 Great Plains, which break into a series of foot-hills along its base ; to 

 the west by a remarkably straight and definite valley occupied by 

 portions of the Columbia, Kootanie and other rivers. 



Since the early part of the century the trade of the fur companies 

 has traversed this range, chiefly by the Athabasca and Peace River 

 Passes, but till the explorations effected by the expedition under Capt. 

 Palliser in 1858-59 nothing was •known in detail of the structure of 

 the range. At the inception of explorations for the Canadian Pacific 

 Railway, Palliser's map was still the only one on which any reliance 

 could be placed, and it applied merely to the portion of the range south 

 of the Athabasca Pass. During the progress of the railway explora- 

 tions a number of passes were examined, and in 1883 and 1884 that 

 part of the range between the 49th parallel and latitude 51° 30" was 

 explored and mapped in some detail in connection with the work of 

 the Canadian Geological Survey by myself and assistants. 



Access to this, the southern portion of the Rocky Mountains within 

 Canadian territory, being now readily obtained by the railway, its 

 mineral and other resources are receiving attention, while the magnificent 

 alpine scenery which it affords is beginning to attract the attention of 

 tourists and other travellers. 



The results of the reconnaissance work so far accomplished are 



