INTER-HOG-BACK VALLEYS. 159 
Usually the slope away from the side of the mountain corresponds 
above with the dip of the rock, and is gentle or steep, as the dip is lesser 
or greater. The side of the hog-back, next to the mountain, is composed 
of the cut edges of the strata, and varies greatly with the texture of the 
rock, but usually it is steep or broken, sometimes buttressed, sometimes ter 
raced, sometimes columned and^fluted. 
On the south side of the Yampa Plateau, near the head of Cliff Creek 
Valley, there is an abrupt, oblique flexure, on the side of the great fold, by 
which the rocks are turned up, so as to stand vertically. In the rocks at 
this place there are two very hard conglomerates ; the intervening strata are 
soft sandstones and marls, and have been carried away, and the conglomer 
ates stand as vertical walls, thirty or forty feet in thickness, fifty to three 
hundred feet in height, and several miles in length, and between these is a 
broad avenue, or narrow valley, beset with ragged boulders of conglomerate. 
The drainage of these narrow valleys between the hog-backs is not 
always along their lengths, but the water is sometimes carried by channels 
crossing them and cutting through intervening ridges ; hence there are num 
bers of transverse streams and wet weather channels running across valleys 
and through ridges. 
Now, if the great axis of the Uinta Fold was everywhere the summit 
of a water-shed, we should mid the streams heading along that irregular 
line running off to the flank of the fold on either side ; but, as the fold is 
bisected by Green River, some of the minor water courses, especially those 
near the river, and those near the center of the fold, follow the strike of the 
rocks directly into that stream. On the north side, some head back near 
the summit of the fold, and run to the north, crossing the hog-backs in a 
direction with the dip, and then turn, at the foot of the mountains, and run 
into the Green, where the waters take a general southerly direction. Others, 
again, head back on the hog-backs, or even beyond them, on the plains and 
the bad-lands to the north, and cut quite through the hog-backs and mount 
ains in a direction against the dip of the rocks, and empty into the Green. 
This is especially true where the river has its easterly and westerly direc 
tion through Brown's Park. On the other side of the range, streams head 
high up in the mountains, and cut directly or obliquely against the upturned 
