The Last of the Plainsmen 



&quot; I can for this part of it. But what stumps me 

 is the mountain range three thousand feet high, cross 

 ing the desert and the canon just above where we 

 crossed the river. How did the river cut through 

 that without the help of a split or earthquake? &quot; 



&quot; I ll admit that is a poser to me as well as to 

 you. But I suppose Wallace could explain it as 

 erosion. He claims this whole western country was 

 once under water, except the tips of the Sierra 

 Nevada mountains. There came an uplift of the 

 earth s crust, and the great inland sea began to run 

 out, presumably by way of the Colorado. In so 

 doing it cut out the upper canon, this gorge eighteen 

 miles wide. Then came a second uplift, giving the 

 river a much greater impetus toward the sea, which 

 cut out the second, or marble canon. Now as to the 

 mountain range crossing the canon at right angles. 

 It must have come with the second uplift. If so, 

 did it dam the river back into another inland sea, 

 and then wear down into that red perpendicular 

 gorge we remember so well? Or was there a great 

 break in the fold of granite, which let the river con 

 tinue on its way? Or was there, at that particular 

 point, a softer stone, like this limestone here, which 

 erodes easily? &quot; 



&quot; You must ask somebody wiser than I.&quot; 



&quot; Well, let s not perplex our minds with its origin. 



250 



