ORIGINAL STREAMS; AND THEIR ROLE IN GENERAL 
DESERT-LEVELING 
CHARLES R. KEYES 
Of all continental features rivers seem longest to persist through 
the geologic ages. The ocean’s strand-line freely oscillates as 
relatively the land-surface rises or sinks, but watercourses flowing 
to the sea are little disturbed. They may be turned aside; but 
they usually quickly adjust themselves to the new conditions by 
merely lengthening or shortening their lower reaches. Some 
streams, we know, hold their original courses in spite of all orogenic 
obstacles thrown across their paths. Others conform closely to the 
local warpings of the earth’s crust. Still others greatly extend 
their valleys by headward growth. But whether antecedent, 
consequent, or subsequent rivers, they are all directly descended 
from prior drainage-systems which stretch out indefinitely through 
geologic time and which even trace back their ancestry to the very 
beginnings of continents. Nowhere and at no time is there spon- 
taneous generation of new streams or total extinguishment of old 
ones. Indeed, in a normally humid climate it could hardly be 
otherwise. In this respect, recorded observation and the necessary 
consequences of theory strictly accord. 
In arid regions there appear to be certain phases of drainage 
which have no counterpart in moist lands. What little running 
water there is, is confined mainly to the slopes of the loftier desert 
ranges. In the mountainous deserts of southwestern United States, 
for instance, the rivers which once traversed the region and which 
once were supposed to have carved out the present great valleys 
are regarded as having long since lost all traces of their courses. 
With increasing aridity came general withering of streams. Hence 
only remnantal drainage now seemingly remains. The head- 
waters of the small intermittent streams are regarded as represent- 
ing all that is left of former great rivers which have vanished under 
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