THE CHATTANOOGA CAMPAIGNS. 



l 5i 



its active weathering, thus the rale of recession of a cliff is entirely regu- 

 lated by the recession of the overcapping stratum. The general result 

 upon the topography is high, cliff-like valley walls, and rather level- 

 topped hills with steep slopes. Where the plateau meets the great 

 valley, this is shown on a grand scale. From Chattanooga northeast- 

 ward along Walden's ridge for scores of miles stretches a cliff or escarp- 

 ment which overlooks the valley. It is steep and the streams flowing 

 across the escarpment have gashed it into a serrate profile which gives 

 it the local name of Cumberland Mountain. The lack of roads and 

 general inaccessibility of plateau and escarpment made it a factor to 



General view showing one of the Appalachian Valley Ridges in Monkoe 

 County, Tenn. (Photographed by the U. S. Bureau of Forestry.) 



be reckoned with in the movement of armies. The plateau is heavily 

 timbered and, in contrast with the valley, is difficult of access and 

 sparsely settled. The relief map of the Chattanooga district shows the 

 surface appearance of these divisions. 



The drainage of these regions is as peculiar and characteristic as 

 are the surface features. The great valley is a structural valley, and 

 not, as are most valleys, the seat of a great river. Its existence, as has 

 before been noted, is due not to river activity, but to the easy denuda- 

 tion of its rocks as compared with those on either side. The only large 



