EARTH FEATURES SHAPED BY RUNNING WATER 173 



plished and the rivers have sunk their early valleys within the 

 new upland, we may look out from this now elevated surface 

 and the eye take in but a single horizontal line, since we view 

 the plain along its edge. 



By the uplift the meanders of the earlier rivers may become 

 entrenched in the new upland, the wide lobes of the individual 

 meanders being now separated by mountains where before had 

 been plains of silt only. The New River of the Cumberland 

 plateau and the Yakima River of central Washington (Fig. 181) 

 furnish excellent American examples of intrenched meanders, as 



FIG. 181. The Beavertail Bend of the Yakima Canon in central Washington 

 (after George Otis Smith). 



the Moselle River does in Europe. Upon the course of the latter 

 river near the town of Zell a tunnel of the railroad a quarter of 

 a mile in length pierces a mountain in the neck of a meander 

 lobe in which the river itself travels a distance of more than six 

 miles in order to make the same advance. The Kaiser Wilhelm 

 tunnel in the same district penetrates a larger mountain included 

 in a double meander of the river. Although intrenched, river 

 meanders are still competent to scour and so undermine the 

 outer bank, and with favoring conditions they may by this process 

 erode extended " bottoms " out of the plateau. (See Lockport 

 quadrangle, U. S. G. S.) 



The valley of the rejuvenated river. Whenever a new uplift 

 occurs before an erosional cycle has been completed, the rivers 

 become intrenched, not in a peneplain, but in the 'bottoms of 

 broad valleys. The sweeping curves which characterize mature 



