6 
Bulletin 77. 
clear days. If the sun-motor is ever perfected, it will be a great 
help to this region, for on days when the wind does not blow the 
sun shines, and the sun-motor would do the work now done by 
horse-powers and gasoline engines. 
Hail. During the eight years we have been at work at Chey¬ 
enne Wells, several hailstorms have struck the place. However, 
no hail sufficiently severe to kill the trees has yet struck there. 
We doubt that fruit trees and crops generally are destroyed by 
hail any more frequently there than in irrigated regions of Colo¬ 
rado. 
Natural Vegetation. Vegetation grows according to the 
water supply. Most of the country is covered by short grass. In 
some places, not more than one-fourth of the ground is covered, 
while in other places where extra water runs on from surrounding 
land, the grass makes a complete mat, covering the whole surface. 
The sand hills and the black sandy land support a variety of tall- 
growing grasses, which usually grow in bunches, but often grow 
two to three feet high. The low places often support different 
species of Agropyron, or Colorado Bluestem — which starts 
early in the season and matures early in July—mak¬ 
ing its growth during the season of maximum rainfall. This 
grass is called “wheat grass” by many, and its habits may be a 
hint for those who wish to depend upon wheat raising in the 
plains region. Some do think that if they could get a variety of 
wheat which would mature by July 4th, it would be practically 
sure to produce a crop every year. The region between the Arick- 
aree and the North Fork of the Republican River, lying east of 
the sand hills, appears like a piece of country taken from two 
hundred miles east of its present location and set down in Eastern 
Colorado. Along the Black Wolf and Dry Willow are fringes of 
trees and plum thickets, and wild grapes are quite common there. 
The rainfall is about the same as in other parts of the Plains. 
Water. The water courses of the Plains are mostly sinuous 
lines of sand of width rudely proportionate to the areas drained. 
They may carry no water for one or two vears, and then a heavy 
rain may come which changes them to raging torrents. The 
J o o 
water does not run down their courses; it just tumbles, scooping 
out great holes here and making immense sand dykes there. If 
there is enough water, some of it joins some running stream, but 
as frequently, it tumbles along over the sandy bed until all is used 
in saturating the upper layers of sand. The surplus caught in the 
water holes goes into that indefinite, much-dreamed-of body of 
water called the underflow. Sometimes this underflow of the 
plains streams follows the course of the present sand-bed, and 
sometimes it does not. The Plains seem to have an infinite num- 
