The pastures consist of valley, mesa and mountain lands which, in
a normal season, are covered by a variety of nutritious grasses.
Of all the native forage plants the gramma grass is the most
abundant and best. It grows only in the summer rainy season
when, if the rains are copious, the gray desert is converted into
a vast green meadow.
The annual rainfall is comparatively light and insufficient to
grow and mature with certainty any of the cereal crops. When the
summer rains begin to fall the rancher is "jubilant" and the "old
cow smiles." Rain means even more to the ranchman than it does
to the farmer. In an agricultural country it is expected that
rain or snow will fall during every month of the year, but on the
range rain is expected only in certain months and, if it fails to
fall then, it means failure, in a measure, for the entire year.
Rain is very uncertain in Arizona. July and August are the rain
months during which time the gramma grass grows. Unless the rain
falls daily after it begins it does but little good, as frequent
showers are required to keep the grass growing after it once
starts. A settled rain of one or more days' duration is of rare
occurrence.
