FORESTS, RESERVOIRS, AND STREAM FLOW 253 
processes just described. These curves apply more particularly to the 
forests of the Rocky Mountains, where the writer has had exceptional 
opportunities for studying their action. In the northwest corner of 
Wyoming and in contiguous portions of the adjoining States, lies an 
elevated region of probably 20000 sq. miles, which is the source of 
nearly all the great river systems of the West. It is a very remark- 
able region in this respect. Its average altitude is about 7500 ft., 
-and it is in large part covered with a dense evergreen forest. At the 
very summit of this elevated region is that singular section now visited 
annually by thousands of tourists—the Yellowstone Park. The open- 
ing of the tourist season in spring occurs just about the time of 
active snow-melting, and the most onerous and difficult task of those 
in charge of the road system of the Park is to get the roads into condi- 
a APRIL MAY JUNE JULY 
GRAPHIC ILLUSTRATION OF SNOW MELTING IN FORESTS AND OPEN COUNTRY, 
ROCKY MOUNTAIN REGION, 
Fie. 1. 
tion for the first travel. This frequently has to be done while the 
snow still lies deep on the ground. It was the repeated execution of this 
task that first drew the writer’s attention to the fact that, as a general 
rule, the floods of this region are forest floods, and that the same condi- 
tions of precipitation which force the forest streams out of their 
banks produce only moderate effects in the open. The traditional 
“June rise” comes mainly from the mountain forests. 
The photographs presented herewith were taken about the middle 
of June in a year of heavy snowfall and only two days before the 
tourist season opened. Fig. 1, Plate XX XVII, shows an east and west 
road through a dense forest of lodge-pole pine at an altitude of 8 200 ft. 
It shows very effectively the deep, even blanket of snow everywhere 
covering the ground, except along a narrow strip at the roots of the 
