44 ELEMENTARY FORESTRY. 



do well than those planted in sections of greater rainfall, and 

 we should not expect them to grow as large as in the timbered 

 sections without irrigation. 



RAINFALL AND HEIGHT OF WATER TABLE IN THE LAND. 



A few years ago it was argued by many friends of tree plant- 

 ing that it was practicable by the planting of trees to increase 

 the rainfall and prevent evaporation in the great continental 

 plain sufficiently to materially change the climate. The large 

 rainfall and the good crops produced for a number of years in 

 the drier portions of this area after considerable planting had 

 been done seemed to endorse all that the most enthusiastic of 

 tree planters claimed. But it must be very evident to any care- 

 ful student of the subject that such small plantings as were made, 

 even had they been maintained, could scarcely have had any 

 appreciable effect on the general climate of so vast a territory. It 

 is very 'evident, too, from a study of the annual rainfall, that it 

 has fluctuated greatly in this section, and that we have perhaps 

 not recorded the least or the greatest amount for any one year. 



There are some facts that seem to show plainly that there 

 must have been a time when the water level of our lakes was 

 much lower than it is now or than it was during the very dry 

 years from 1890 to 1895, when the rainfall in most cases pro- 

 duced no flow in the streams. There is a lake near Devils Lake, 

 N. D., where in 1890 the old overland trail leading west termi- 

 nated abruptly on one side of the lake and was taken up again 

 in the continuation of its direction on the opposite side. The 

 trail is clear and distinct, showing it to have been of compara- 

 tively recent use. It is a reasonable inference that when this 

 trail was in use this lake was dry. There are places near the 

 shores of Devils Lake where upright stumps are standing sub- 

 merged in water. The same phenomenon has been noticed in 

 other places. These are almost certain indications of a time 

 or times when the beds of these lakes, where the stumps arc. 

 were out of water or very nearly so for a sufficient length of 

 time for the trees to grow. The climate must have been very 

 dry, and the great continental plain, or at least portions of it. 

 must have bordered pretty closely upon a desert, and the "Great 

 \mrnrun Desert" may have been a reality. It would seem. then. 



