24 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 
prospects of the inter-montane area, we have but few facts and few con- 
clusions to present that we consider of special importance, and these re- 
late almost entirely to Northern Utah and Eastern Idaho. The portion 
of this inter-montane section within the locust area consisting of Idaho, 
Western Wyoming, Western Colorado, Utah, and Nevada offers but 
little prospect of extension of agricultural operations within its bounds. 
It is not probable that of the 375,000 square miles contained in this area 
more than 25,000 to 30,000 square miles will be brought under cultiva- 
tion for a century to come, its chief value being its mineral resources. 
The chief agricultural area at present, and the only one to which we shall 
call attention at this time, is the belt running north and south through 
the central part of Northern Utah and Southeastern Idaho. 
As shown by our first report the region around Salt Lake is subject to 
repeated locust invasions from the north, apparently the resulting broods 
of the swarms that originate in that portion of Montana of which we 
have been speaking, and which pouring over the mountain pass at the 
head of Jefferson River, move down Snake River Valley. 
If the scheme we have suggested should be carried out and should 
prove beneficial in reference to the eastern area, it would have, to some 
extent at least, a like effect as to this section. If it is possible to estab- 
lish and maintain an agricultural population in the Upper Snake River 
Valley, this would have a strong tendency to modify the evil. But the 
present barren aspect of this region would seem to forbid any hopes of 
ever accomplishing this desired end. Still there appears to be one pos- 
sible means of bringing this about, at least to a limited extent. The de- 
mand of trade will doubtless complete the railroad already started in 
that directiou which is one step toward the desired end, but something 
more is required in this case. 
Snake River affords a large body of water which if properly utilized 
would irrigate a large breadth of land, and notwithstanding the barren 
appearance of the soil it is really fertile when irrigated. It is possible, 
with a moderate expense, to throw dams across this stream at certain 
favorable spots, and by this means to spread the water over the adjoin- 
ing plains.- A work of this kind would of course have to be done by the 
general government. The feasibility of this project could easily be as- 
certained by an officer of the Engineer Corps of the Arcny ; and as this 
is on the line of the chief inter-montane thoroughfare and also of the 
locust invasions of this region, the subject is certainly worthy of the at- 
tention of the government. 
As will be seen by what we have presented on this subject, the philoso- 
phy of our plan for modifying the evil is to place an agricultural popula- ' 
tion in the very home of the species, which from necessity would be 
compelled to wage a constant warfare against them. 
By stirring the soil their nests would be disturbed; by fighting the 
young their numbers would be diminished ; and as irrigation would be 
necessary the effect of dry seasons on the crops would not be felt as in 
