Forests and Snow. 
5 
rarely found in tracts burned over or denuded of timber. It is the water 
from these springs which maintains the flow of the rivers from Sep¬ 
tember to April. Their decrease is cause for alarm. Within the past 
few years the Poudre at one time fell to less than forty cubic feet per 
second. April and May are the months of heaviest rainfall; most of 
the continued storms occur during these months. Yet, our river rec¬ 
ords, now carried on for nearly twenty years, show that these rains have 
comparatively little effect. A rise in the river due to a storm is dis¬ 
tinguishable from one due to melting snow, as may be seen from the 
diagrams. The snows show a daily tide, usually at the same hour. 
The rises due to storms are irregular in time and character. An un¬ 
expected effect is that rains in the mountains usually decrease the 
amount of water. The cloudiness associated with the storms prevents 
more thawing than the rain supplies. 
If the area covered by snow has been extensive and extends to a 
relatively low elevation, with the coming of warm weather the snow 
melts soonest on the low areas. As a rule these are less protected 
from the rays of the sun. Melting proceeds, even to considerable ele¬ 
vations, in the direct rays of the sun, though freezing may be going on 
at the same time in the shade, as on the north side of the ridges. A 
forest cover protects from the direct rays of the sun just as the ridges 
do. 
In the middle of the summer, snow is to be found at moderate 
elevations only in the forests or under ridges where sheltered from the 
direct rays of the sun. As melting proceeds the tributaries are swollen, 
and the main streams increase in volume, their maximum being reached 
long before the greatest heat of summer. Though the melting is faster, 
the snow areas are so much less that the aggregate is reduced, hence, 
the stream decreases. 
Figure 1. 
