PLATE V 



FIG. 1. Youthful topography in a region of slight relief. The valley of Maple 



. Creek is narrow, and much of the area is unaffected by erosion. Scale, 



al >niit 2 miles per inch. Contour interval, 20 ft. (X. D., U. S. Geol. Surv.) 



j i,,. -j. A young valley in a region of great relief. Scale, about 2 miles per 

 inch. Contour interval. Km fri-t. (U. S. Geol. Surv.) 



