636 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



The knolls along Dry Brook near Rutledge are sometimes in groups, 



but quite as often are isolated. There are also di-ift ridges, a notable 



example being found just east of Rutledge, which leads north to south 



' directly across the valley of Dry Brook. It is fully one-half mile long and 



30 to 40 feet in height. 



The knolls are less conspicuous north from Dry Brook on the east 

 tributaries of Conewaugo Creek, though, as above noted, the drift is heavy 

 in the vicinity of Leon, and has a gently undulating surface. 



The uplands between Conewango and South Cattaraugus creeks carry 

 only a few knolls, and there are but few in South Cattaraugus Valley below 

 Maples post-office. But on the meridian of Maples morainic features appear 

 quite abruptly on both sides and in the bottom of South Cattaraugus 

 Valley. The knolls are large enough to be distinctly visible on hills a mile 

 distant to the south, and are equally large to the north, being in some 

 instances 15 to 25 feet in height. They are larger in the valley bottom 

 than on the slopes. 



The moraine is well developed toward the east from Maples as far as 

 the present head of an eastern branch of South Cattaraugus Creek. It 

 there blocks the valley so greatly that the former headwater part has 

 been turned south into a tributary of Great Valley, which it enters at 

 Ellicottville. There is a gravel outwash from the moraine forming a plain 

 that covers perhaps 60 acres at the present water parting, and reaches to 

 the point where the stream to the east cuts across the old col. The moraine 

 presents a ridge or chain of knolls only 10 to 20 feet high at the west 

 border of this gravel tract. 



The moraine does not rise to the high ridge on which Plato post-office 

 stands, which is fully 2,100 feet above tide, but sweeps around its north 

 slope, passing within a half mile of the post-office. It carries a large 

 number of bowlders as well as hummocks and low ridges of drift. 



Eastward to the head of Ashford Hollow the moraine presents numer- 

 ous low hummocks 5 to 10 feet high. These dot the slopes and bottom of 

 the hollow for over a mile from its head. In the interval between Ashford 

 Hollow and West Valley the knolls are less sharp, but the drift is heavy 

 and fills up depressions among the rock ridges sufficiently to cause some 

 changes of draiuag'e. 



In West Valley the moraine forms a water parting which is apparently 



