No. 374] VEGETATION OF WESTERN NEBRASKA. 113 
tain mahogany (Cercocarpus parvifolius) in great abundance on 
the steep slopes. Here the pine is the principal tree, growing 
abundantly in the deep cafions and upon the exposed mesa-like 
summits of the rocky spurs. 
After we reach the top of Cheyenne Ridge, we find broad 
stretches of grassy meadow land which are comparable to the 
mountain meadows of the great range to the westward ; and 
yet here the summits, which here and there rise 100 meters 
or more above the general elevation, are capped and fringed 
with pines. The Wildcat Mountains constitute one of these 
series of higher summits, attaining an altitude of fully 1700 
meters, and their summits and slopes, as well as tortuous 
cafions, bear pine trees here massed and there widely scat- 
tered. From the highest point of Cheyenne Ridge, as we pass 
southward, there is a gradual return to the type of Agropyron- 
Stipa-Bouteloua-Lepidium which we found on the high plains 
north of the North Platte River. As we pass ridge after ridge, 
each a little lower than the preceding, we gradually lower our 
elevation until we run down into the valley of the Lodge Pole 
River, 1450 meters above the sea. The last ten kilometers 
have nearly duplicated the floral covering of the Box Butte 
Plains, with somewhat less of the effects of aridity in its gen- 
eral aspect, and with here and there a cottonwood, box-elder, 
or willow tree along the river to relieve the monotony of the 
landscape. 
