Our Northern Rockies 



3 6 3 



The weary climbing through heavy 

 snow is replaced by long, exhilarating 

 slides down the hard slopes, the spike 

 of the alpenstock scratching a deep 

 track in the snow and our knees aching 

 with the long tension, and at nightfall 

 we reach camp, to find that every gunny- 

 sack, many saddle blankets, and the 

 front of my waterproof coat have all 

 been eaten by the hungry mules. 



The Mission Range is the western- 

 most of the several ranges which col- 

 lectively represent the Rocky Moun- 

 tains, and it receives more rain and 

 snow than the ridges to the eastward, 

 being the first to intercept the moisture- 

 laden winds from the southwest. The 

 range is much steeper on the western 

 slope than on the eastern, which is ac- 

 counted for by the geologic structure ; 

 but at the top of the ridge so much 



glacial erosion has taken place, so many 

 amphitheaters and deep gorges have 

 been cut, that the crest is broken into 

 a number of isolated peaks. 



We find it is made up of a series of 

 limestones, which dip to the northeast, 

 with some quartzite and intrusions of 

 igneous rock, the west face being a 

 fault plane. The stratification and dip 

 of the beds are clearly shown in the 

 view on page 371. This may be taken 

 as a type of the ranges west of the 

 Continental Divide. 



To the east of the Mission Range 

 lies Swan Valley, extending some 55 

 miles north and south and being about 

 10 miles wide. It is drained by Swan 

 River, which heads in the snow and 

 ice fields of the Sin-yel-a-min Peak and 

 Jocko Crags and flows northward for a 

 time in a narrow, ice-cut gorge, now 



We start for the pass and peak (McDonald) by the easiest route 



