222 
THE GEAND CAS^ON DISTEICT. 
backwards. We should rather conceive of the platforms as being cut by a 
labyrinth of drainage channels, ramifying over their entire expanse, and 
as being attacked within and without, and all around — as a great conflagra- 
tion spreads through every square, street, and alley of a city. A state of 
affairs quite similar to that suggested here seems to prevail at the present 
time in the interior spaces of the Plateau Province. The drainage basins 
of the Escalante River, of the San Juan, and indeed of that entire part of 
the Colorado which reaches from the junction of the Grand and Green to 
the head of Marble Canon, are wonderfully dissected by countless canons, 
which I am confident were in existence at this very epoch, though they 
have since been gi’eatly deepened and otherwise modified. 
It may also be of interest to inquire whether it is probable that canons, 
architectural cliffs, buttes, and mesas existed in the Miocene, similar to 
those now occurring. The answer to this must be largely conjectural, but 
it seems to me that the probabilities are against such a topography. The 
present features of the region are no doubt favored greatly by an arid cli- 
mate. Still we know that canons and cliffs may be generated in moist 
climates. But under a moist climate, other circumstances and conditions 
must be of a very exceptional nature to produce such features, and even if 
produced, they are evanescent. An arid climate not only tends to produce, 
but also tends to maintain them. Under a moist climate the tendency is 
to reduce them to normal forms. Further than this it seems useless to 
speculate. 
• The first indications of specialized events are associated with the 
beginning of the present Grand Canon.* About the time that the river 
began to cut into the Carboniferous strata, some important physical changes 
in the condition of the region took place, which have left their imprints 
upon the topography. The climate appears to have changed from moist to 
arid. In preceding chapters we have noted particular instances where this 
change manifests itself in the drying up of lateral streams. Perhaps the 
* I use the term “present Grand Canon” to designate the state of the canon at the present time 
in the Carboniferous, in contradistinction to the more ancient state of the valley. All through this 
work the idea is kept in view that this valley in earlier times lay within Mesozoic strata, which have 
been swept away from the vicinity of the river, and now appear only in the terraces, fifty miles or more 
to the northward. 
