LEWIS RANGE 311 



and Waterton rivers, and extends southeastward to about latitude 46 de- 

 grees 45 minutes. It will be designated the Lewis range after Captain 

 Meriwether Lewis, who in 1806 was the first white man to cross it. As 

 the Lewis range does not extend far north of the 49th parallel, the 

 western crest becomes in Canada the easternmost heights of the Rocky 

 mountains, and it has there been called the Livingston range. This 

 name is herein adopted and applied to the mountains as far south as 

 mount Heavens near McDonald lake. Here the Livingston range appears 

 to fall away and lose its identity. Between the Lewis and Livingston 

 ranges is an elevated valley in which Waterton river and the tributaries 

 of McDonald lake have their sources, the former flowing northerly, the 

 latter southwesterly from a flat-topped mountain in the heart of the range. 



From the Great plains prominent spurs of Lewis range rise very boldly 

 in the mountains known as Divide, Red Eagle, East Flattop, Yellow, 

 and Chief, and in the heights west of Belly river. Looking at one 

 of these promontories in profile it may be seen to present towards the 

 northeast a bold and even precipitous scarp (figure 1, plate 47), from the 

 foot of which the line of slope of the Great plains descends gently east- 

 ward. These mountain promontories carry the contours between 8,000 

 and 9,000 feet elevation as much as ten miles out to the northeastward 

 from the main crest of the Lewis range. Between them are valleys ex- 

 cavated at elevations between 4,500 and 5,000 feet above the sea, which 

 extend at moderate level very nearly to the crest of the range, and end 

 in radiating canyons, under cliffs that rise boldly about their heads (see 

 plate 46). They are also bounded along their sides by cliffs which out- 

 line the promontories (figure 2, plate 47). Thus the eastern margin of 

 the Lewis range is deeply sinuous, and the heights above the general 

 altitude of the Plains are marked off by cliffs from the lower slopes. 

 The promontories are commonly sharp ridges of mature form, but are 

 sometimes broad. That which lies between Boulder creek and Saint 

 Mary lakes, and which is called East Flattop, carries a broad plateau- 

 like summit at 7,000 to 8,000 feet above sea. This summit is unsym- 

 pathetic to its environment and represents an older phase of topography. 

 The slopes of the valleys exhibit soft and rounded forms, due either to 

 erosion of incoherent clay shales, to deposition of glacial drift, or to 

 numerous landslides. 



The crest of the Lewis range is everywhere narrow, and in many 

 places is a knife edge of jagged rocks. The precipices by which it is 

 defined are frequently more than a thousand feet in height, and in some 

 instances attain an altitude of 4,500 feet with a slope that is nowhere 

 below 50 degrees. These cliffs are the walls of profound amphitheaters, 

 usually occupied by lakes. The sculpture is that which is characteristic 



