PHYSICAL CHARACTERISTICS OF THE ARID REGION. i 
from the lake is carried by the westerly winds to the adjacent mountains 
on the east and again condensed, and the rainfall thus produced extends 
somewhat beyond the area occupied by the mountains, so that the foot hills 
and contiguous bench lands receive a modicum of this special supply. In 
some seasons this additional supply is enough to water the lands for remu- 
nerative agriculture, but the crops grown will usually be very small, and 
they will be subject to seasons of extreme drought, when all agriculture 
will result in failure. Most of these lands can be irrigated, and doubtless 
will be, from a consideration of the facts already stated, namely, that crops 
will thereby be greatly increased and immunity from drought secured. 
Perhaps other small tracts, on account of their subsoils, can be profitably 
cultivated in favorable seasons, but all of these exceptions are small, and 
the fact remains that agriculture is there dependent upon irrigation. Only 
a small part of the territory, however, can be redeemed, as high, rugged 
mountains and elevated plateaus occupy much of its area, and these 
regions are so elevated that summer frosts forbid their occupation by the 
farmer. Thus thermic conditions limit agriculture to the lowlands, and 
here another limit is found in the supply of water. Some of the large 
streams run in deep gorges so far below the general surface of the country 
that they cannot be used; for example, the Colorado River runs through 
the southeastern portion of the Territory and carries a great volume of 
water, but no portion of it can be utilized within the Territory from the fact 
that its channel is so much below the adjacent lands. The Bear River, in 
the northern part of the Territory, runs in a somewhat narrow valley, so 
that only a portion of its waters can be utilized. Generally the smaller 
streams can be wholly employed in agriculture, but the lands which might 
thus be reclaimed are of greater extent than the amount which the streams 
can serve; hence in all such regions the extent of irrigable land is depend- 
ent upon the volume of water carried by the streams. 
In order to determine the amount of irrigable land in Utah it was 
necessary to determine the areas to which the larger streams can be taken 
by proper engineering skill, and the amount which the smaller streams can 
serve. In the latter case it was necessary to determine first the amount 
of land which a given amount or unit of water would supply, and then the 
