one hundred miles of canon,
the river emerges upon a desert region, where the rainfall is so
slight that curious and unusual forms of plants and animals have
been developed, forms which are adapted to withstand the almost
perpetual sunshine and scorching heat of summer.

Below the Grand Canon the river traverses an open valley, where
the bottom lands support a few Indians who raise corn, squashes,
and other vegetables. At the Needles the river is hidden for a
short time within canon walls, but beyond Yuma the valley widens,
and the stream enters upon vast plains over which it flows to its
mouth in the Gulf of California.

No portion of the river is well adapted to navigation. Below the
canon the channels are shallow and ever changing. At the mouth,
enormous tides sweep with swift currents over the shallows and
produce foam-decked waves known as the "bore."

Visit the Colorado River whenever you will, at flood time in early
summer, or in the fall and winter when the waters are lowest, you
will always find it deeply discolored. The name "Colorado" signifies
red, and was given to the river by the Spaniards. Watch the current
and note how it boils and seethes. It seems to be thick with mud. The
bars are almost of the same color as the water and are continually
changing. Here a low alluvial bank is being washed away, there a
broad flat is forming. With the exception of the Rio Grande in
New Mexico, and the Gila, which joins the Colorado at Yuma, no
other river is known to be so laden with silt. No other river is
so rapidly removing the highlands through which it flows.

[Illustration: FIG. 2.--LOOKING DOWN THE COLORADO RIVER FROM ABOVE
THE NEEDLES]

Over a large portion of the watershed of the Colorado the rainfall
is light. This fact might lead one to think that upon its slopes
the work of erosion would go on more slowly than where the rainfall
is heavy. This would, however, be a wrong conclusion, for in places
where there is a great deal of rain the ground becomes covered
with a thick growth of vegetation which holds the soil and broken
rock fragments and keeps them from being carried away.

The surface of the plateaus and lower mountain slopes in the basin
of the Colorado are but little protected by vegetation. When the rain
does fall in this arid region, it often comes with great violence.
The barren mountain sides are quickly covered with trickling streams,
which unite in muddy torrents in the gulches, carrying