152 
The Ohio Naturalist. 
[Vol. IV, Ko. 1 , 
glacial history of the region. Near the western end, Pleasant 
Run enters the abandoned portion of the valley from the north, 
flows diagonally across it toward the southwest and enters a nar- 
row valley about one mile long, the southern end of which opens 
into the Hocking valley. This narrow valley is about 300 yards 
wide at its narrowest point and is bordered by very steep rock 
walls 150 to 200 feet high. The floor is a level plain, in every way 
a continnation of the floor of the larger valley. There are no well 
borings which might show the depth of drift. It is not in a 
position for an oxbow of either the Hocking or the stream which 
formerly occupied the abandoned valle}’. It is possible that there 
may have been a low col in this narrow valley over which the 
waters from the east poured after their outlet at Lancaster had 
been blocked by ice but before the present outlet had been cut. 
Subsequent advance of ice might have blocked this outlet and the 
present drainage have been developed. 
Little Rush Creek rises in Perr}- county near New Reading and 
flows westward into Fairfield county, entering Big Rush Creek 
at Bremen. In its upper cour.se its valle}' is broad and two and 
one-half miles northeast of Rushville a depth of 160 feet was 
reached with no rock. A short distance above Rushville it begins 
to narrow. At the station a depth of 40 feet was penetrated with- 
out encountering rock, but a few hundred yards below, the valley 
becomes extremely gorge-like and the stream flows on rock, 
everything indicating the site of a col. This region was prol ably 
drained to the northwest into the preglacial outlet of the Mus- 
kingum, although the channel is now difficult to trace. A low, 
broad depression extends from a short distance above Rushville 
through to this old valley. 
Clear Creek enters Hocking from the west about three miles 
below Sugar Grove. Its headwaters are in a rolling, drift-covered 
region not far from the headwaters of the Hocking, but its valley 
fir.st becomes well defined near Amanda, where it is more thnn a 
mile wide and is bordered Iw rock hills. It narrows gradually, 
however, and near Revenge becomes very gorge-like although 
there is a flood-plain .several hundred feet wide. About four 
miles above its juncture with Hocking, it narrows perceptibh' 
until the flood-plain is not more than 100 yards in width, the hills 
being very abriqrt and about 200 feet or more in height. Below 
this point the valley widens .somewhat but not much. This nar- 
row point is an old col. The preglacial outlet of Clear Creek is 
buried beneath drift deposits but was probably northwest from 
Amanda into the Scioto. 
A valley extends from Lancaster southwest to Amanda, con- 
necting the Clear Creek and Hocking valleys. At Lancaster it 
is about one mile wide but it narrows until, at Dehnont five miles 
distant and 250 feet above Lancaster, it is about 300 j-ards in 
