dry land dips several hundred feet below the level of the ocean.
Only by extreme siccity is such land possible when more water
rises in evaporation than falls by precipitation. There are but
few such places in the world, the deepest one being the Dead Sea,
which is about thirteen hundred feet lower than the ocean.

The Colorado Basin is the dry bed of an ancient sea whose shore
line is yet visible in many places upon the sides of the
mountains which surround it. Its floor is composed of clay with
deposits of sand and salt. Strong winds sometimes sweep over it
that shift and pile up the sand in great dunes. The entire
region is utterly bare and desolate, yet by the use of water
diverted from the Colorado river it is being reclaimed to
agriculture.

The rainfall is very scant the average annual precipitation at
Yuma being less than three inches. The climate is not dry from
any lack of surface water, as it has the Gila and Colorado
rivers, the Gulf of California and the broad Pacific Ocean to
draw from. But the singular fact remains that the country is
extremely dry and that it does not rain as in other lands.

Neither is the rainfall deficient from any lack of evaporation.
Upon the contrary the evaporation is excessive and according to
the estimate of Major Powell amounts fully to one hundred inches
of water per annum. If the vapors arising from this enormous
evaporation should all be condensed into clouds and converted
into rain it would create a rainy season that would last
throughout the year.