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 Gambler, 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 Gambler it is in the ancient bed which here divided a chan- 

 nel extending northward toward Martinsburg, now filled with gravel 

 and sand bills, 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 Kijlbuck, 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. 



I 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 Gambler, to the bed 

 of Owl Creek, indicates very clearly a chapter of this old history. 



