MOUNT RAINIER 



sufficient to feed and maintain so extensive an ice 

 field as lies stretched out under them. Surely much 

 more snow must annually melt away from the broad 

 surface of that field, exposed as it lies to the midday 

 sun, than the insignificant avalanches can replace. 

 Were they its only source of supply, the ice field, one 

 feels confident, would soon cease to exist. 



The fact is that the ice field in question is not de- 

 pendent for its support on the avalanches from above. 

 It may receive some contributions to its volume through 

 them, but in reality it is an independent ice body, 

 nourished chiefly by direct snow precipitation from the 

 clouds. And this is true, in large measure, of all the 

 ice fields lying under the ice cascades. The Nisqually 

 Glacier, accordingly, is not to be regarded as composed 

 merely of the cascading neves, reunited and cemented 

 together, but as taking a fresh start at these lower 

 levels. Improbable though this may seem at first, it 

 is nevertheless a fact that is readily explained. 



The winter snows on Mount Rainier are heaviest in 

 the vicinity of its base ; indeed, the snowfall at those 

 low levels is several times greater than that on the 

 summit. This in itself may seem anomalous. So ac- 

 customed is one to think that the snowfall on high 

 mountains increases with the altitude that it seems 

 strange to find a case in which the opposite is true. 

 Yet Mount Rainier stands by no means alone in this 

 regard. The Sierra Nevada and the Andes, the 

 Himalayas and the Alps, all show closely analogous 

 conditions. 



In each of these lofty mountain regions the precipi- 

 tation is known to be heaviest at moderate altitudes, 

 while higher up it decreases markedly. The reason is 

 that the storm clouds the clouds that carry most of 

 the rain and snow hang in a zone of only moderate 

 elevation, while higher up the atmosphere contains 

 but little moisture and seldom forms clouds of any 

 great density. 



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