20 WILD AXIMALS OF GLACIER NATIONAL PARK. 



mals include the Richardson and thirteen-lined ground squirrels, the 

 Saskatchewan pocket gopher, and the prairie hare; while the west- 

 ern vesper sparrow, western Savannah sparrow, western chipping 

 sparrow, lazuli bunting, yellow warbler, and long-tailed chickadee 

 are characteristic birds. 



On the west slope of the park traces of the zone are seen in the 

 yellow pines in the North Fork Valley, a few mountain junipers 

 along the river banks, black thornapple along the lake shores, west- 

 ern birch along the streams, and an abundance of serviceberrics, 

 syringa, ocean spray, and Ceanothus sanguineus on the low, warm 

 slopes ; but no considerable area can be called Transition Zone. The 

 climate of these low valleys is mild, but the snowfall is so heavy and 

 the timber growth so dense that melting snow, delayed late into 



Fig. 1. — Open Transition Zone valley. Yellow pines on and along edge of Big Prairie 

 in North Fork Flathead Valley, looking east to Vulture Peak. April 16, 1918. 



spring by the cool forest shade, favors the plant growth and the 

 animal life of the Canadian Zone, which dominates the valleys. 



CANADIAN ZONE. 



Tlie Canadian, which comprises the well-timbered areas of the 

 park, is the most extensive of the four life zones. It reaches from 

 practicallj' the base of the park all around up to altitudes of approxi- 

 mately G,000 feet on northeast slopes and 7,000 feet on southwest 

 slopes, varying somewhat with the steepness and soil cover and 

 with the amount of sunlight allowed to reach the surface of the 

 ground. Most of the zone is covered by heavy forests of lodgepole 

 pine, Engelmann spruce, subalpine fir, aspens, black cottonwood, 

 and mountain maple, but over the lower part of the west slope of the 



