3 86 
Journal of Agricultural Research 
Vol. I, No. 5 
Table: VI. —Salt content of the soil at points where Artemisia tridentata and Atriplex 
confertifolia grew side by side. 
Depth of 
soil. 
Salt content in boring No.— 
59 
60 
95 
96 
Feet. 
1 
2 
3 
4 
Per cent. 
o. 06 
.27 
Per cent. 
O. 08 
• 53 
Per cent. 
O. 12 
• 53 
I. 02 
I. 36 
0 
"JO 0 § 
Os-fik -fc. SS 
Sagebrush with Juniper. —The Utah juniper ( Juniperus utahensis) 
is abundant on the lower slopes of the mountains and also pushes 
down into the upper part of Tooele Valley, where it occurs scatteringly 
in the midst of areas occupied by the typical sagebrush association (see 
background of PI. XLIV, fig. i), as well as on the sand hills. The pres¬ 
ence of juniper away from the sand hills usually indicates a stonier soil 
than that on which the typical sagebrush association occurs. 
SAND-HILL MIXED ASSOCIATION 
Topographical Relations 
The sand-hill mixed association covers a limited area towards the 
south end of the valley, lying directly in the path of the winds from the 
southwest which sweep over the low divide separating Tooele Valley 
from Rush Valley. Even when the air is nearly motionless in other 
parts of the valley, a sandstorm may often be seen blowing in this quar¬ 
ter. The sand is mostly heaped in dunes, which form more or less 
continuous ridges having a general north and south trend. In places 
where “blow-outs” have taken place the ground is sometimes bare, 
but for the most part it is fairly well covered with vegetation. 
Appearance and Botanical Composition 
As is usually the case in arid regions, the vegetation of the sand hills 
is characterized by the presence of a large number of species—far more 
than occur in any other plant association of Tooele Valley. The appear¬ 
ance of the vegetation as viewed a short distance away is determined by 
the presence of a few woody species, notably sagebrush (Artemisia triden¬ 
tata) and juniper ( Juniperus utahensis). Sagebrush is much the most 
abundant of the woody plants of the sand hills, and the individual 
plants of this species which grow there are the largest and thriftiest 
found anywhere in Tooele Valley under natural conditions. 
The Utah juniper is fairly abundant on the sand hills. It occurs 
as a large shrub or small tree, rarely exceeding io feet in height. Two 
species of rabbit brush (Chrysothamnus nauseosus albicaulis and C . 
pumilus) are also common, while the remaining woody species of this 
