belief that a large portion of the area receiving less than 10
inches of rainfall, annually, will ultimately be reclaimed without
irrigation.

Naturally, not the whole of the vast area just discussed could be
brought under cultivation, even under the most favorable conditions
of rainfall. A very large portion of the territory in question is
mountainous and often of so rugged a nature that to farm it would be
an impossibility. It must not be forgotten, however, that some of
the best dry-farm lands of the West are found in the small mountain
valleys, which usually are pockets of most fertile soil, under a
good supply of rainfall. The foothills of the mountains are almost
invariably excellent dry-farm lands. Newell estimates that
195,000,000 acres of land in the arid to sub-humid sections are
covered with a more or less dense growth of timber. This timbered
area roughly represents the mountainous and therefore the nonarable
portions of land. The same authority estimates that the desert-like
lands cover an area of 70,000,000 acres. Making the most liberal
estimates for mountainous and desert-like lands, at least one half
of the whole area, or about 600,000,000 acres, is arable land which
by proper methods may be reclaimed for agricultural purposes.
Irrigation when fully developed may reclaim not to exceed 5 per cent
of this area. From any point of view, therefore, the possibilities
involved in dry-farming in the United States are immense.

Dry-farm area of the world

Dry-farming is a world problem. Aridity is a condition met and to be
overcome upon every continent. McColl estimates that in Australia,
which is somewhat larger than the continental United States of