The Grand Canyon may be likened to an inverted mountain range.
Imagine a great mountain chain cast upside down in plaster. Then all
the former ridges and spurs of the range become tributary canyons and
gulches running back twenty or thirty miles into the surrounding
country, growing shallower and shallower as the distance increases
from the central core, just as the great spurs and ridges of a
mountain range, descending, melt finally into the plain. Often there
are parts where the central gorge is narrow and precipitous, just as
a mountain range frequently possesses mighty precipices. But it is an
error to think of great canyons as mere slits in the ground, dark and
gloomy, like a deep well from whose depths stars may be sighted at
midday. Minor canyons sometimes approach this character, as, for
example, the canyon of the upper Virgen, called Parunuweap, fifteen
hundred feet deep and no more than twenty to thirty feet wide, with
vertical walls, but I have never been in a canyon from which stars
were visible in daylight, nor have I ever known anyone who had. The
light is about the same as that at the bottom of a narrow street
flanked by very high buildings. The walls may sometimes be gloomy
from their colour, or may seem so from the circumstances under which
one views them, but aside from the fact that any deep, shut-in valley
or canyon may become oppressive, there is nothing specially gloomy
about a deep canyon. The sun usually falls more or less in every
canyon, no matter how narrow or deep. It may fall to the very bottom
most of the day, or only for an hour or two, depending on the trend
of the canyon with reference to the sun's course. At the bottom of
the Kanab where it joins the Grand, the sunlight in November remains
in the bottom just two hours, but outside in the main gorge the time
is very much longer.