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FLORA OF GLACIEE NATIONAL PARK, MONTANA. 



By Paxtl C. Standley. 



INTRODUCTION. 



Glacier National Park lies in northwestern Montana along tlie 

 main range of the Rockies. It embraces an area of 1,534 square 

 miles, nearly all of which consists of masses of high mountains. 

 On the north it adjoins British Columbia and Alberta; eastward 

 stretch the prairies of the Blackfoot Indian Reservation, and to the 

 west lie the mountains and heavy forests of the Flathead Valley. 

 The Continental Divide runs along the crest of the chief mountain 

 ridge. The drainage of the west (Pacific) slope of the park is conse- 

 quently into the Columbia River, while on the east (Atlantic) slope 

 it is partly to Hudson Bay and partly to the Missouri River. From 

 one point, Triple Divide Peak, the drainage is partly into each of the 

 three systems. The highest peaks of the region reach an altitude of 

 but little more than 3,000 meters (10,000 feet), but the elevation of 

 the surrounding country is comparatively low (950 meters on the 

 west slope and 1,440 meters on the east slope), so that the mountains 

 are quite as imposing in appearance as many of those in the southern 

 Rockies which have a much greater elevation. 



The rocks of the park are stratified and of Algonkian age. They 

 consist chiefly of shale, limestone, sandstone, and argillite, their pre- 

 vailing colors being rich reds and dull greens. In many places the 

 stratification is very regular and certain strata can be traced with the 

 _^eye for many miles, but in other places the strata are folded and con- 

 torted in an interesting fashion. Besides the stratified rocks, a con- 

 ^ spicuous feature is an intrusion of diorite — an igneous rock — which 

 J can be followed for a long distance along the Garden Wall as a well- 

 - marked band of black. 



^ The whole region of the park is extremely rugged (see plate 33), the 

 9 mountains usually having sharp summits and precipitous sides. The 

 main ridge is broken only infrequently by passes, whose altitudes 

 range from 1,800 to about 2,100 meters. The slopes of the mountain 

 masses have been plowed by ancient glaciers, and numerous lateral 

 valleys have been cut, along which streams now run. In many of the 

 valleys lie large or small lakes whose waters are wonderfully trans- 

 parent and beautifully colored in blue or green. Fed directly by 



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