56 



ever, that the western portions of Dakota, Nebraska, Kansas, the In- 

 dian Territory, and Texas, partake of the semi-arid condition of the 

 region of the plains and indeed constitute a part of it, and have iden- 

 tical interests. Their grazing and farming industries are conducted 

 upon principles similar to those which govern the like operations of 

 their neighbors westward, and dependence upon the streams flowing 

 from the mountains is as marked in one instance as in the other. 



Oregon and Washington lie at the northwest. They, also, in their 

 eastern portions, require water for irrigation. Their great river, the 

 Columbia, is kept at a navigable stage by the large tributary streams 

 which flow from the mountains. 



At the west and southwest, the contiguous Territories of Utah and 

 Arizona fall within the Arid Belt. The needs of their increasing pop- 

 ulation and rapidly developing industries require that the timber and 

 water supplies of the mountains shall be maintained in perpetuity. 



CLIMATE. 



The atmospheric conditions of the Rocky Mountain region, as affect- 

 ing the life and health of those who are living under their influence, 

 have been a subject of quite general interest, and thus the leading char- 

 acteristics of the region in this respect are known to many. 



A concise statement of the climatic conditions of the region is given 

 in the ofiicial report for 1885 of Hon. Francis E. Warren, governor of 

 Wyoming, to the Secretary of the Interior, I take the liberty of quot- 

 ing as follows : 



Were it not for the lieat of the tropiccal regions, which is distributed over the con- 

 tinent by atraospberic currents as well as by tbe thermal ocean and Gulf currents, tbe 

 high elevations of the Eocky Mountain regions would be too rigorously cold for hab- 

 itation. But through these tempering influences they are not only habitable, but 

 delightful and healthful portions of the continent, far more so than the Atlantic coast, 

 or the great river valleys which approximate the sea-level on either side of the great 

 continental divide. The humid tropical winds and the equatorial warm Japanese 

 currents of the North Pacific Ocean — which are similar to the Gulf Stream of the 

 Southern Atlantic— reaching the western and southern shores of the continent, pro- 

 duce the mild and even temperature of these coasts and, with climatic modifications, 

 extend to the elevated Rocky Mountain regions of the interior. 



These modifications are mainly produced by the high snow-capped and almost un- 

 broken mountain ranges of the western coast — the Cascade and the Sierra Nevada, the 

 latter of which is covered with dense forests to an elevation of some 8,000 feet, while 

 still above this lies perpetual snow. These, to some degree, are barriers against the 

 extension of the warm atmospheric currents of the ocean over the interior Rocky 

 Mountain elevations. Hence, as these mild winds, heated by the tropical ocean cur- 

 rents, sweep over the snow-capped mountain ranges, and around their extremities, 

 and thus pass over vast arid regions in their course to the great Rocky Mountain ele- 

 vations, they become somewhat tempered, and give to them their salubrious climate. 

 The moisture that comes upon the mountain ranges, in the way of rain, during the 

 rainy seasons of the Pacific coast, is slight from January to May. 



It may be said further, that the superior elevation of this great cen- 

 tral plateau, its remoteness from the sea or other large bodies of water, 



