352 The Ohio Naturalist. [Vol. VIII, No. 7, 



Recognizing the fact, as all of us probably do, that valleys 

 are made by streams, and, in similar rocks are proportionate in 

 size and form to the size of the stream and the length of time 

 the latter has had to work, it becomes very apparent that we 

 have an anomalous condition here, where the larger streams 

 Black and Muddy Forks flow in broad open valleys, then in 

 narrow^ ones and again in broad ones, while some small streams 

 are in much broader valleys than they could possibly have made 

 during the time at their disposal. These are the features that 

 appeal at once to the traveler and invite his attention if not his 

 curiosity. 



Upon looking a little more carefully other items in the prob- 

 lem are found. In the course of Mudd}'' Fork from Lakefork 

 village to Lakeville, and of Black Fork from Loudon ville to the 

 Mohican, not only do the valleys narrow but the upland topo- 

 graphy changes as the narrowest portion of the valley is reached. 

 The high hills become more youthful and draw in closer to the 

 present main valley, suggesting that formerly at these two 

 narrows, streams once headed and flowed away in opposite 

 directions. In accordance with a law of valley development, 

 that youth is more marked near the headwaters, this theory 

 accounts for the more youthful character of the slopes and form 

 of valley at the narrows. 



The side streams entering these two sections of the courses 

 of Muddy and Black Forks respectively, have a story to tell. 

 North of the narrows they enter with their small angles down 

 stream contrary to the normal habit of stream arrangement, 

 and south of the narrows they enter in a thoroughly normal 

 manner with the small angle up stream, suggesting that, at pres- 

 •ent, the flow of the main stream north of the narrowest places 

 is in the reverse direction from that of the stream occupying the 

 valleys when the drainage patterns were outlined ; but that in 

 the portions south of the narrowest places, the flow is in the 

 same direction as during the early history of the region. 



It has already been suggested that Muddy and Black Forks 

 have cut at their respective narrows new gorges in rock, through 

 what was formerly a low rock divide between small streams 

 flowing in opposite directions. Still further confirmation of 

 this hypothesis is found in the small laterals entering the main 

 stream jiear the narrows. The side stream entering Muddy Fork 

 nearest Lakefork shows a very little rejuvenation and down 

 cutting in its mature higher valley in order that the stream may 

 enter Muddy Fork at grade. In the case of the side stream next 

 nearer the narrows, the mature valley seems to hang higher above 

 the level of Muddy and to have a deeper recent gorge valley in 

 its bottom. The third and fourth hang still higher and the re- 

 cent gorges are still deeper. Moreover the mature hanging 



