QUATERNARY AGE. 305 



traveling along and near the Niobrara, roots of pine trees were 

 often found sticking in the ground, more than fifty miles south and 

 east of the present forests of this timber. Often did these old roots 

 furnish me with the materials of a camp fire. At no very remote 

 period pine forests must have flourished down to the mouth of the 

 Niobrara. Many other facts, of a similar character, seem to leave 

 no room to doubt that in geologically recent times far more exten- 

 sive forests prevailed all over Nebraska than those which now oc- 

 cupy the ground. What caused their disappearance can, perhaps, 

 not be certainly determined. Some geologists hold that the in- 

 creasing dryness of the climate caused the disappearance of any old 

 forests that might have existed. But might not the converse of this 

 also have been true here, as well as elsewhere, namely, that the de- 

 struction of forests inaugurated the dry climate that prevailed when 

 thU territory was first explored? It is at least conceivable that the 

 primitive forest received its death-blow in a dry summer by fire, 

 through the vandal acts of Indians in pursuit of game or for pur- 

 poses of war. What suggested this theory as a possible explanation 

 of the disappearance of forests on this territory, was the finding of 

 pine roots before referred to, and often, when partially, buried, 

 showing marks of fire from carbonized ends, and in localities so 

 sandy, and where vegetation was so scant, that an ordinary prai- 

 rie fire was out of the question. An old tradition that I once heard 

 from the Omaha Indians points to the same conclusion. 



It is wonderful how nature here responds to the efforts of men 

 for reclothing this territory with timber. Man thus becomes am 

 efficient agent for the production of geological changes. As prai- 

 rie fires are repressed and trees are planted by the million, the cli- 

 mate must be still further ameliorated. When once there are- 

 groves of timber on every section or quarter- section of land in the 

 State, an approach will be made to some of the best physical con- 

 ditions of Tertiary times. The people of this new State have a- 

 wonderful inheritance of wealth, beauty and power in their fine 

 climate and their rich lands, and as they become conscious of this 

 they will more and more lend a helping hand to the processes of 

 nature for the development and utilization of the material wealth of 

 Nebraska. 



Causes of Changes of Climatic Conditions During the Quaternary 

 Age. Every geologist has noted the fact that there have been very- 

 many changes of climate during the progress of the worl<JV history,. 



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