326 GEOLOGY OF OHIO. 
Summit county. A similar channel, passing diagonally through Ash- 
land county, having Savannah Lake as its Summit, invites the atten- 
tion of railroad engineers. In Richland county, all the railroads for the 
greater part of their course follow the ancient valleys. In Knox county, 
Owl Creek and the Sandusky branch of the Baltimore and Ohio Rail- 
road occupy the channel to Mt. Vernon, where the stream takes the 
eastern branch of the pre-glacial valley to Coshocton county, and the 
railroad the southern branch into Licking county. For a part of the 
distance below Mt. Vernon and Gambier, the stream has made for itself 
an independent channel through rock spurs projecting from the north, 
but the course of the old river can easily be traced a little to the north 
of it. At Gambier it is in the ancient bed which here divided a chan- 
nel extending northward toward Martinsburg, now filled with gravel 
and sand hills, and occupied by Big Run, which flows northward, a 
direction opposite to that of the old stream, and becomes a tributary to 
Owl Creek. At Millwood, also, the channel of Owl Creek is narrow, 
rock-bound, and recent, but the old channel is easily traced to the south 
of the massive bluffs of the Waverly Conglomerate, where it is now 
filled with modified Drift hills of gravel and sand. 
Coming down from the divide between the waters of Owl Creek and 
the Killbuck, the engineers who surveyed the route of the Cleveland, 
Mt. Vernon and Coshocton Railroad, and who had followed one of these 
old channels most of the way from Akron to Oxford, turned into this 
ancient valley, finding a level surface, no rock cuts, easy material to ex- 
cavate, and abundance of gravel. 
A railroaa from Mt. Vernon to Coshocton could be built only by follow- 
ing this old pre-glacial channel. 
These old valleys have been filled by glacial Drift to the summit of the 
adjacent hills, and probably nearly if not quite to the top of the highest 
hills in the county ; the immense erosion which accompanied the retreat 
of the glacier sweeping away the great bulk of the Drift, taking all 
the finer materials, and leaving a residuum of sand and gravel. 
The following section from Zion’s church east of Gambier, to the bed 
of Owl Creek, indicates very clearly a chapter of this old history. 
