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THE POPULAR SCIENCE MONTHLY. 



there are numbers 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 sum- 

 mit of a water-shed, we should find the streams heading along that 

 irregular line running ofi' to the flank of the fold on either side ; hut, 

 as the fold is bisected by Green River, some of the minor water- 

 courses, especially those near the river, and those near the centre of 

 the fold, follow the strike of the rocks dircictly 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 

 mountains in a direction against the dip of the rocks, and emj^ty into 

 the Green. This is especially true where the river has its easterly and 

 westerly direction 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 edges of the strata, and run in a gen- 

 eral direction with the dip of the strata until they reach the long val- 

 leys between hog-backs; then down these valleys they turn, some- 

 times cutting through intervening ridges, until they find their way 

 into the Green, where they are turned to the south, away from the 

 mountain. 



FiQ. 7. An Anaclinai Vallet. 



Tt will thus be seen that the relation of the direction of the streams 

 to the dip of the rocks is very complex, and, for convenience of de- 

 scription, I have elsewhere classified these valleys, on the basis of 

 these relations, in the following order : 



Order 1. Transverse valleys, having a direction at right angles to 

 the strike. 



