systems and practices, not more than 10 per cent will be reclaimed
by irrigation. Dry-farming is truly a problem to challenge the
attention of the race.






CHAPTER IV

DRY-FARM AREAS.--GENERAL CLIMATIC FEATURES





The dry-farm territory of the United States stretches from the
Pacific seaboard to the 96th parallel of longitude, and from the
Canadian to the Mexican boundary, making a total area of nearly
1,800,000 square miles. This immense territory is far from being a
vast level plain. On the extreme east is the Great Plains region of
the Mississippi Valley which is a comparatively uniform country of
rolling hills, but no mountains. At a point about one third of the
whole distance westward the whole land is lifted skyward by the
Rocky Mountains, which cross the country from south to northwest.
Here are innumerable peaks, canons, high table-lands, roaring
torrents, and quiet mountain valleys. West of the Rockies is the
great depression known as the Great Basin, which has no outlet to
the ocean. It is essentially a gigantic level lake floor traversed