SCIENTIFIC EXPEDITION TO NORTHWESTERN COLORADO 



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and Rangely 5,050 feet above sea-level. The aridity of the climate at 

 Rangely is recognized at once by the record of precipitation. Meeker 

 with a rainfall nearly twice as great must, however, be included with 

 Rangely as arid. This will be apparent by comparison with the climate 

 of Denver. Denver has a mean annual rainfall of but 14 inches as com- 

 pared with 16 inches at Meeker, and yet the vegetation about Denver 



Fig. 4. — Graphic representation of the mean precipitation by months at Meeker, 

 Rangely, Boulder and Wray. The stations, Meeker and Rangley, west of the continental 

 divide, have an even distribution of rainfall throughout the year, as is shown by the flatness 

 of the curves for these stations. On the other hand, Boulder and Wray, stations east of 

 the main range, have the greater percentage of their rainfall during the spring months. 



is not as xerophytic in its nature as that about Meeker. This difference 

 is due in large measure to the seasonal distribution of rainfall. At 

 Meeker and Rangely, in fact at all localities west of the continental 

 divide, only about 50 per cent, of total precipitation occurs during the 

 growing season. On the other hand, at Denver, and other stations 

 east of the main range, about 75 per cent, of the yearly precipitation 

 comes during the growing season. Fig. 5 shows graphically the distri- 

 bution of precipitation throughout the year for stations near the 40th 

 parallel both east and west of the continental divide. Judging from 

 annual precipitation amounts alone leads one into error unless there be 

 a consideration of seasonal distribution 



