densest of known rocks. As you stand on the rim of this most 

 magnificent of nature's spectacles, you may well ponder these 

 facts; and the more you do so. with the object before you. the 

 more mystified you will become. 



Geologists have done this for a century, but they have not, in 

 my opinion, as yet come up with any satisfactory explanation. 

 The theory usually propounded is that this block of mountains 

 started rising only about a million years ago and that, as it did 

 so. the Colorado River managed to counteract the rise by cutting 

 this vast gorge over 200 miles through its midst. Now this could 

 conceivably have been the case if the river had had to deal with 

 only soft muds and clays and an occasional thin layer of 

 sandstone or other sedimentary rocks: but it just could not in 

 those circumstances have done what must have been done to 

 the very hard rocks at the bottom, at which point its cutting 

 power was at its lowest ebb. One thing is sure — the Grand 

 Canyon was not formed entirely during the Pleistocene, even if 

 there was a great enough volume of water bearing enough sedi- 

 ment to carve it out during all the interglacial periods. 



The Colorado River followed that channel long before the 

 Pleistocene, and there is reason to believe that it had been doing 

 so since the beginning of the Eocene, some fifty-five million years 

 earlier, and that it had already scoured out an impressive gorge 

 by the beginning of the Pleistocene ice advances. The whole of 

 this province, along with the rest of the Rockies, had been 

 steadily rising since the beginning of the Eocene. Moreover, strata 

 laid down later than that period, though massive both to north 

 and south of the Colorado Plateau, are today entirely absent 

 from it, though there is every reason to suppose that they once 

 existed all over it as a continuous blanket. Where did all this 

 vast mass of material go? Could it all have been carried away 

 by the meltwater from the modest glaciers and icefields of the 

 surrounding inountains in less than a million years? 



Furthermore, the whole area is said to have been lower at 

 that time, yet this river cut through the hardest rocks when it 

 was at its lowest level. How was this physically possible? Then 

 again, all evidence from the rocks laid down around the plateau 





The Sage Grouse, better called the Sage Hen (Centrocercus 

 urophasianus), inhabits the scrub belt between the 

 Cascade—Sierra Nevada ranges on the west and the Rockies 

 on the east. It is also found all over the Colorado Plateau 

 and in sagebrush and semidesert areas throughout the 

 southern Rockies. It is an impressive bird, but is rather lum- 



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