84 GEOLOGICAL SURVEY OF THE TERRITORIES. 



low bluff-like wall, ten to twenty feet above the level of the water. It 

 seems to have come down the ravines in the hills bordering the valley, 

 and to have spread out like the slag from a furnace. The river seems 

 to have stopped its progress, for no trace of the rock could be found on 

 the south side. It seems to have forced the river to the southern side 

 of the valley, and the force of the water has scooped out the hills, leav- 

 ing bluffs on that side in which the strata forming the hills are beauti- 

 fully shown. 



