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 stood 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. 
Pelow the col, as mentioned before, the valley 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 vallej' the stream has been forced by 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 we.st of the narrow flood-plain is occupied b}- 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 where it joins Arne}' 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 at the southern side 
whatev'er blocked the old outlet has been removed, and there is 
an opening 100 }'ard.s wide where the dam is only a few feet 
above the present level of the tributary. At no point is the dam 
as high as the deepest ]>art of the rock gorge. It is probable that 
ice which melted afterward aided greatly in blocking the old 
channel. It is po.ssible 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 
are 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 which 
has been mentioned. xVbont three miles .southwest of Lancaster, 
as it enters this valley it passes through a narrow constriciion 
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 impres.sed by 
