156 The Ohio Naturalist [Vol. IV, No. 7, 



Lancaster the valley is filled with irregular drift deposits in which 

 a small, northward flowing stream and its tributaries have cut 

 deep trenches with narrow flood-plains. 



Prior to the advance of the ice there was a divide at Jacob's 

 Ladder, one stream flowing to Clear Creek, another toward Lan- 

 caster. The ice advanced as far as the drift dam and jtood at 

 this point for some time, blocking the outlet and forcing the 

 stream over the col at Jacob's Ladder. This, in time, was cut to 

 the present level. While in this position, the ice deposited the 

 debris in the mouth of the valley which prevented the return of 

 the stream to the old channel after the advent of a milder climate 

 and the retreat of the ice. 



Below the col, as mentioned before, the valle}' again broadens, 

 and at the point where it enters Clear Creek is about half a mile 

 wide. In the immediate vicinity of the col there is no drift, but 

 about one mile below drift terraces occur on both sides, the one 

 on the west being more prominent. From this point to the mouth 

 of the valley the stream has been forced b)- the ice to the east 

 wall and flows in a narrow flood-plain, in at least one place pass- 

 ing over a rock bottom where it has been forced over a shelf. 

 The valley west of the narrow flood-plain is occupied by drift 

 deposits 50 to 100 feet above the stream. 



About one and one-half miles below the col a tributary- enters 

 from the east. Its valley whore it joins Arney Creek is about 

 300 yards in width, but it has been so blocked up at this point 

 that the stream has been forced to cut a channel in the rock of 

 the north wall. This channel is 100 feet deep, 200 yards long 

 and barely wide enough for the small streamlet and a narrow 

 wagon road. The sides are of rock and very steep. Much of the 

 dam remains in the form of drift on the northern side of the 

 valley just south of the rock channel, but .it the southern side 

 whatever blocked the old outlet has been removed, and there is 

 an opening 100 yards wide where the dam is onh* a few feet 

 above the present level of the tributary. At no pohit is the dam 

 as high as the deepest part of the rock gorge. It is probable that 

 ice which melted afterward aided greatly in blocking the old 

 channel. It is possible that this dam is the extreme outer limit 

 of the Late Wisconsin ice sheet at this point, as drift deposits to 

 the west are abundant and uninterrupted while to the east they 

 art- unknown to the writer. 



Hunter's Run, in the lower part of its course occupies the east- 

 ern end of the valley extending from Lancaster to Amanda wliich 

 has been mentioned. About three miles southwest of Lancaster, 

 as it enters this valley it passes through a narrow constriction 

 between two high sandstone hills. Above this point the valley 

 is not so well defined. There are rock hills on the south, but 

 looking toward the north from these hills, one is impressed by 



