TOPOGRAPHY 25 



Granite Mountain near Cooke, just northeast of Yellowstone 

 Park, 12,847 feet (38). 



The Continental Divide enters Montana on the north at about 

 the 114th meridian nearly 100 miles east of the western boundary 

 of the State. Its direction from that point is southeastward for 

 over 200 miles to a point near the city of Butte, where it swings 

 westward about 75 miles thence 100 miles southeast to the Yel- 

 lowstone National Park. In the north it is identified with the 

 Livingston Range which, with a rugged crest 7000-9000 feet 

 elevation, traverses the Glacier National Park. Here it is mag- 

 nificent, precipitous and glacier-ridden, where the "Garden 

 Wall" thrusts a serrated sky-line between the eastern and west- 

 ern drainage. The altitude of the Divide, however, has a wide 

 range of variation. At Summit, where the Great Northern Rail- 

 way crosses, it has an altitude of 5214 feet. South of this point 

 it rises again to 8000 and 9000 feet with passes below 6000 until 

 it curves westward near Butte. From here to its junction with 

 the Bitter Roots it is relatively low (5500-7000) and is either 

 forested or denuded by fires. From this point to the Yellowstone 

 Park, the Divide, though somewhat higher, is rounded, broad and 

 may be traveled with comparative ease. Along the southern 

 boundary of the State it separates the waters of the Snake River 

 from the ultimate sources of the Missouri. The total length of 

 the Divide, from the northern boundary of Montana to the Yel- 

 lowstone Park, is upward of 500 miles. 



The Bitter Root Range is variously defined. On some maps 

 it is shown as extending from Clark's Fork of the Columbia to 

 Yellowstone Park. Lindgren (34) limits it to 60 miles, north 

 and south trend, from Lolo Pass to the Little West Fork of the 

 Bitter Root River. At this point the geological formations 

 change and southward the structure of the range identifies it 

 with the Rocky Mountains. This portion, generally included 

 in the Bitter Roots, is a northward projecting spur of the Main 

 Divide. With the Bitter Roots proper it forms a natural boun- 

 dary wall between Montana and Idaho, and divides the tribu- 

 taries of the Clark's Fork, the Snake, and the Missouri. 



The Bitter Root Mountains rise abruptly from the western 

 side of the valley of the same name. The crest of the range 

 lies at an averasre of about fifteen miles from the Bitter Root 



