SCIENTIFIC EXPEDITION TO NORTHWESTERN COLORADO II 5 



Colorado, all near the 40th parallel, two on each side of the continental 

 divide. (See Fig. 1 for their relative locations.) 



From the table it is seen that the mean annual range of tempera- 

 ture is greater in the case of the two localities, Meeker and Rangely, 

 west of the divide, than it is for Boulder and Wray, stations east of the 

 divide. As a general rule, annual range of temperature decreases with 

 an increase of altitude. Meeker, however, has a greater elevation than 

 Boulder, but a wider range of temperature. The annual march of 

 temperature is given in Fig. 5 for Meeker, Rangely, Boulder and Wray. 



The average length of the growing season at Meeker is 95 days; the 

 average date of last killing frost in spring, June 7 ; and of first killing 

 frost in autumn, September 12. These conditions, together with the 

 severity of the climate, limit horticultural possibilities. Peaches or 

 melons cannot be successfully grown. Some varieties of apples and 

 cherries, however, do well. Hay is a more profitable crop than grain. 



A Botanical Trip in Northwestern Colorado 

 By W. W. Robbins 



For the botanist there is keen pleasure connected with collecting 

 in fields new to him. There is the anticipated enjoyment of getting new 

 species, possibly; of seeing new plant-formations; of making comparisons 

 with the flora and vegetation with which he is familiar. In Colorado 

 there are many new botanical fields. One who has done most of his 

 botanical field-work on plains and in mountains east of the continental 

 divide is always eager to see what is "on the other side of the mountain. " 

 It is generally held, and correctly too, that the flora and vegetation west 

 of the continental divide is essentially different from that to the east. 

 These differences will be mentioned at another point. 



General account. — The first three weeks of August were spent riding 

 and tramping through a country of stream-cut valleys, some wide and 

 gently sloping at either side, others narrow and abrupt, bounded on 

 both sides by sedimentary ridges. During this time we did not get 

 above an altitude of 7,500 feet, and hence through it all there was a 

 sameness and monotony to the vegetation. The general character of 



