35 2 
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 Muddy Fork from Lakefork 
village to Lakeville, and of Black Fork from Loudonville 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 confirrr^tion of 
this hypothesis is found in the small laterals entering the main 
stream near 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 
