No. 50.] 
441 
leys has once been occupied by lakes which have been gradually drain- 
ed, some in one direction and some in the other. 
The great depressions on the south and west, the valleys of the Al- 
legany river and Lake Erie, have given direction to all the water cour- 
ses of Cattaraugus county and the southern part of Genesee. 
The valley of the Olean creek from the north joins the Allegany 
at Olean, and at this junction is much expanded. This valley may be 
viewed as taking the course toward the source of the Allegany, having 
the same direction as the valleys farther east. West of Olean, we have 
the two valleys from the north, known as the Great and Little valleys, 
which join the Allegany at its most northerly bend. From this point 
it would have been httle deviation from the general course, for these 
valle3^s to have followed the Allegany valley, either southeast towards 
its source, or southwest in the present direction of the stream. Rea- 
soning from analogy with other valleys of this region, we should sup- 
pose such to have been the former direction of the excavating power 
of these valleys. The evidence at Lodi and other places in that neigh- 
borhood, clearly prove the existence of a large north and south valley 
in that direction ; the same appearances exist at the sources of Great 
and Little Valley creeks, and the south branch of the Cattaraugus. 
The course of the Cattaraugus creek is in a bed or valley of recent 
excavation, produced by the accumulation of water at its source, and 
the sources of its tributaries. 
The Ischua creek flows in the bottom of an ancient valley, which at 
Hinsdale is joined by the Oil creek, also in an ancient valley. The 
valley of the Ischua, is easily traced north as far as Machias, when it 
spreads out to considerable extent. Between this place and the Alle- 
gany, it presents a general broad flat plain, gradually descending to 
the south, and limited on each side by ranges of hills. Its further con 
tinuation north by the valley of Lime Lake, thence northward to the 
Cattaraugus is in some measure obscured by alluvial hills. For some 
distance south of Machias, the bottom of the valley is covered with a 
fine loam, resulting doubtless by deposition from v/ater, while all this 
portion was covered by a lake. 
The Great and Little valleys, the Conewango and Cold-Spring val- 
leys, all apparently result from the division of one large northern val- 
ley, which at Waverly takes these several directions. The country 
[Assembly, No. 50.] 56 
