5° 
The Colorado River 
evenly over a canyon brink, owing to irregularities of surface, 
and once an irregular drainage is established, the water seeks 
the easiest road. A side canyon is formed, draining a certain 
area. Another is formed elsewhere, and another, and so on 
till all drainage is through these tributaries and away from the 
brink, by more or less circuitous channels to the main stream. 
This backward drainage leaves the immediate brink, or “rim,” 
till the last, in its work of erosion and corrasion, and the rim 
consequently is left higher than the region away from it. This 
effect of a backward drainage is very plain on both sides of the 
Grand Canyon, though it is somewhat assisted, on the north at 
Towers at Short Creek. Southern Utah. 
This is a part of the great line of the Vermilion Cliffs. The region here represented possesses some 
of the most magnificent scenery of the whole West. 
Outline drawing by W. H. Holmes. 
least, by the backward dip of the strata. It may be modified 
by other conditions, so that it would not always be the case. 
The basin of the Colorado, excepting that part below the 
mouth of the Virgen and a portion among the “parks ” of the 
western slope of the Rocky Mountain range, is almost entirely 
a plateau region. Some of the plateaus are very dry; others 
rise above the arid zone and are well watered. The latter are 
called the “High Plateaus.” They reach an altitude of eleven 
thousand feet above the sea. They are east of the Great Basin, 
and with the other plateaus form an area called by Powell 
“The Plateau Province.” Eastward still the plateaus merge 
