TOPOGKAPIIICAL FEATURES. 49 



rcf'-ions of the Adirondack and Green Mountains, and covered usually with 

 a heavy growth of timber, but opening out occasionally into grassy park- 

 like valleys, it often vies in wildness and beauty with those better-known 

 mountain regions of the East. Viewed from a height, as from Harney 

 Peak, the area has a billowy appearance — a succession of ridges and peaks, 

 with now and then a stretch or spot of open park — and at first it reveals no 

 system of structure, save that it is cut from west to east by the draining 

 streams which have eroded deep and usually narrow valleys or canons. 

 Though the strike of the rocks is toward the north or northwest, there at 

 first a))})ears no feature in the topography due to this fact, but a closer and 

 more detailed study reveals the presence of a continuous ridge or series of 

 ridges extending on the east side of the area from southeast to northwest ; 

 and in the more minute inspection of the geology along the streams these 

 ridges are seen to have been defined by the presence of paiticularly hard 

 strata, quartzites, etc., through which the several draining streams have cut 

 their way in intricate and deep canons. On the western side of the area a 

 similar belt of prominent and resistant rocks is observed, through which 

 many of the streams have cut narrow gorges. Between these ridges the 

 country, excepting in the region of the Harney Peak granites, is less 

 rugged, and not unfrequently the banks of the streams widen out into val- 

 leys broad and gently sloping. 



Toward the southern end of the Archaean region is a tract of feld- 

 spathic granite the most rugged and mountainous in the Hills. It is 

 characterized by numerous peaks and ridges, of which Harney Peak and 

 Dodge Peak are the most prominent. South of it and quite in the south- 

 ern end of the Archaean are many of the park-like expanses already alluded 

 to, well grassed and devoid of trees, and among them are the largest that 

 are found in the Hills. Several of the most important have received special 

 names, as Custer Park, on the headwaters of French Creek, in which is 

 located Custer City ; Dodge Park, farther southwest, on the headwaters of 

 Red Canon Creek ; and Elkhorn Prairie, on the headwaters of Spring Creek 

 cind the south branch of the Rapid. 



The margin of the Archaean area is bordered continuously by an 

 escarpment more or less abrupt, and usually several hundred feet high, 



4 B H 



