50 PHYSICAL GEOGRAPHY. 



take their place. In other words, whenever the mountain sides 

 become bare of forests, they remain so. It has also been asserted 

 that many groves along the sides of the mountains and on the 

 summits were dying off without any apparent cause, except the 

 increasing dryness of the region. I am now confident that the ad- 

 vocates of this theory are mistaken in their theories and their facts. 

 It is true that since the miocene tertiary age or even since the cre- 

 tacious, the amount of water. in the form of great lakes has on the 

 whole been decreasing. But there are limits to these processes. 

 There have been many revolutions in the condition, geological and 

 meteorological, of central and western North America in the meso- 

 zoic and cenozoic ages. For example, during the earlier ages the 

 greater part of western Nebraska was dry land. But it gradu- 

 ally and slowly commenced to sink, and in the course of centuries 

 that are numberless, the Gulf of Mexico extended itself in a north- 

 westerly direction over our plains to the Arctic sea. The uplift- 

 ing of the Rocky Mountains that commenced at the close of the 

 cretaceous age, inaugurated the area of making of dry land which 

 has continued to the present time, but with many intermissions. 

 My limits will not permit me to discuss these interruptions. But 

 these facts in geological history do not warrant us to conclude, be- 

 cause in the most recent periods the tendency has been to continued 

 elevation and dryness, that this tendency must continue. Rather 

 should the opposite conclusion be reached, that sooner or later the 

 limit of elevation and dryness will be attained, and that a reaction 

 must follow as in the past. This reaction must for countless ages 

 in the future bring increasing moisture. Now, the facts of the 

 present operations of nature in the mountains do not sustain this 

 theory. 



The advocates of the increasing dryness of the mountains evident- 

 ly make many of their observations at "long range." They have 

 viewed mountain sides and tops like some newspaper men have 

 battles a great way off. Commencing at Georgetown I have 

 climbed every mountain side and examined every mountain top 

 that I could see where the timber had been destroyed from any 

 cause. The whole number of such places that I examined was 

 twenty-seven, and in every instance I found countless numbers of 

 young pines and sometimes deciduous trees coming up to take the 

 place of the old ones. Often when I looked at a mountain side 

 from a distance nothing could be seen but old trees deadened by 



