54 
The Colorado River 
water of the Colorado, and the Wind River Mountains on the 
extreme north, have snow-banks throughout the summer. To 
show how dependent the Colorado is on the high peaks for 
its flood-waters, 1 will mention that it is not till the snows of 
these high altitudes are fiercely attacked by the sun in May 
and June that the river has its annual great rise. It would take 
only a slight lowering of the mean annual temperature now to 
furnish these peaks with ice caps. The rainfall in the lower 
arid regions is from three to ten inches, increasing northward 
to fifteen and twenty-five. On the peaks, of course, it is much 
greater. Almost any climate can be had, from the hot arid to 
the wet frigid. On the lower stretches, from Mohave down, 
the thermometer in summer stands around 112° F. a great deal 
of the time, and reaches 118° F. Yet Dr. Coues said he felt 
it no more than he did the summer heat of New York or Wash¬ 
ington.^ In winter the temperature at the bottom of the 
Grand Canyon is very mild, and flowers bloom most of the 
time. One November I descended from the snow-covered top 
of the Kaibab to the Grand Canyon at the mouth of the 
Kanab, where I was able to bathe in the open air with entire 
comfort. 
There are six chief topographical features, canyons, cliffs, 
valleys, mesa plateaus, high plateaus, mountains. There are 
two grand divisions: the lowland or desert, below the Virgen, 
and the plateau, but the topography of the immediate river 
course separates itself into four parts, the Green River Valley, 
the canyon, the valley-canyon, and the alluvial. The canyon 
part is the longest, occupying about two-thirds of the whole, 
or about 1200 miles. It is cut mainly through the plateaus. 
The last of these southward is the Colorado, a vast upheaval 
reaching from the lower end of the Grand Canyon south-east 
to about where the 34th parallel crosses the western line of 
New Mexico. Lieutenant Wheeler several times claims the 
honour of naming it (1868-71), but the name occurs on 
Lieutenant Ives’s map of 1858. This plateau breaks sharply 
along its south-west line to the lowland district, and on its 
' I was at the Needles one summer for a brief time, and the air seemed very 
oppressive to me. 
