[32] 
22 
and its tributaries, offer tlie same features as low down as Marsh 
mountain, from whence their course continues in a deep and narrow 
ravine, with st^ep, and rugged banks. The bottom of these glades, 
which has been sounded in several places, present the following lay- 
ers: 1st. Rich loam. 2nd. Sand, colored by oxydated iron. Sd. Vege- 
table detritics. 4th. Alluvial clay. 5th. A horizontal bank of sand 
stone, four or five feet below the surface, on which the other layers 
all lie. 
The great Youghioglieny, after receiving the little Youghiogheny, 
and Deep creek, receives Bear cre<>k. I'he east branch of this last 
stream rises on the west side of Negro mountain, and runs from south 
to north till it forces its way through Keyser's ridge; it then turns 
suddenly east, and, after forcing through Winding ridge, falls into the 
Youghiogheny. Its west branch springs from the west side of Key- 
ser's ridge, and joins th-e other at the gap wiiere it forces its way 
through Winding ridge. 
Savage river runs on a bed of sand stone, its course is rapid, and 
broad flats extend along both its banks. Crabtree creek is the chief 
tributary stieam which joins it; it runs between the great and little 
Back Bone, and is formed by the junction of Grabby's arm. and Wil- 
son's fork, which take their sources in that part of the little Back 
Bone wiiich divides their ravines from the valley of the little Yough- 
iogheny. Crabby's arm runs in a narrow vale, but which is, howe- 
ver, wide enough to receive a catial; its bottom is a black alluvial 
soil, and its banks present a gentle slope. Wilson's fork is more 
rapid, but runs in a wide and well wooded valley. These two streams 
join at Swan's mill, from whence they impetu«nisly descend on a bed 
from ten to twenty yards wide; they are interrupted in two or three 
places by perpendicular falls, seven or eight feet high, and frequently 
by smaller ra|)ids, which fall from four to five feet. From the great 
Back Bone, Crabtree creek receives several tributaries; they are tor- 
rents which frtil into it with great impetuosity. On both sides of its 
valleys run flats, eight or ten yards wide, which are intersected by 
rugged bluffs, from 100 to 200 feet high, which divide them into iso- 
lated poitions, the bluffs on one side of the stream, lying, in geneial, 
opposite to the flats on the other, and the two banks presenting an 
alternate succession of the same features. 
Such are the main streams which, in this section, descend from the 
two sides of the Aileganies. 
To conduct the canal across this summit ground, we must 1st. Se- 
lect the best passage for it through the little Back Bone, by leading 
it cither from the valley of Savage river, to tliat of Deep creek, and 
from that of Crabtree creek to the same, or from the valley of Crab- 
tree creek, to that of the little Youghiogheny. 2nd. As( ertain which 
of these passages presents the shortest route from the mouth of Savage 
river, to that of Bear cre*^k. 3d. Ascertain, as the most essential 
element of tlie wliole project, whether a supply of water, sufficient for 
all tlie purposes of the canal, can be procured at this elevation. 
W^e shall point out the several passages which lead through the 
