174 Dr Johannes Walther — The North American Deserts. 



The relation of the bed of the Colorado to the canyon can be 

 better recognized, however, if, proceeding along the upper edge 

 eastward, one finally reaches the point seen and described for 

 the first time by the Spanish commander Coronado in 1542. 

 Spanish point lies at the extremity of one of those wooded 

 tongues of land which project so far toward the middle of the 

 gorge that one is able to survey the river for a considerable dis- 

 tance along its middle line. It has already been pointed out by 

 Button, and the view from Spanish point easily shows it, that 

 the canyon is divided into two parts. At the bottom the river 

 is seen rushing along in a narrow gorge cut in gneiss, and our 

 ears catch the muffled roar of the mighty stream that rolls its 

 brown-red flood over rapids and reefs. The bed at times is so 

 narrow that the rocks rise perpendicularly 400 meters from the 

 water, and only on turning northward, where the Little Colorado 

 breaks forth from its narrow gateway of rock, do we see the 

 river bed widening and even bordered by a green fringe of low 

 bushes. 



That this trench traversed by the Colorado and mostly of 

 gorge-like narrowness is an effect of erosion, that it was cut by 

 the river and is still being deepened, is not open to the least 

 doubt ; but when we turn our eyes to the edge of this interior 

 groove of erosion we see at once a different landscape. ' The 

 strata referred to the Silurian and Devonian represent a shelf 

 several kilometers in breadth, designated by Button as the 

 " esplanade." The edges of the strata appear distinctly as deli- 

 cate isohypsal lines, and the valley widens with very gentle 

 slope, to be succeeded again by escarpments 1,000 meters high. 

 But the widening above the esplanade is not uniform ; for the 

 promontory of Spanish point forms a sheer wall only a few 

 kilometers distant from the river, while alongside it deep, semi 

 circular kettles enter 5 to 8 kilometers into the plateau, and 

 thereby carr}'- back the edge of the canyon gorge as far as 10 

 kilometers from the erosion groove of the river. 



Were we to cast a birdseye view on the whole valley system 

 we should see in the middle a uniform, steeply carved groove, 

 which at a certain point of its depth all at once widens greatly 

 and appears fringed with deep, semicircular bays. If from 

 Spanish point we look westward, we gaze into such an amphi- 

 theater. With sheer walls 800 meters high, it rises from the 

 esplanade ; nowhere could the bold foot of a mountain-climber 



