Rocky Mountains. 73 



This gray sandstone appears from the organic relicts it con- 

 tains, as well as from its relative position, to have been of 

 more recent deposition than the red. Its prevailing colours 

 are gray or yellowish white, its stratifications distinct, and 

 its cement often argillaceous. 



After entering upon this variety, we found the valley of 

 the creek less serpentine in direction, but narrower and more 

 obstructed by detached fragments than below. The impaling 

 cliffs on each side were also more uniformly perpendicular, 

 putting it out of our power to choose any other path than 

 the rugged one which lay before us. As with every step of 

 our advance upon this route we were gaining a little in point 

 of elevation, we hoped by following it, to reach at length, its 

 termination in the high and open plain which we had no 

 doubt existed, extending over the greater part of the surface 

 of the country wherever the strata of sandstone were still 

 unbroken. At five P. M., supposing we had arrived very 

 near this wished-for spot, and finding an indifferent supply of 

 grass for our horses, we halted for the night, having travel- 

 led fifteen miles. 



26th. The water of the large stream we had crossed and 

 ascended for some distance on the preceding day, was tur- 

 bid, and so brackish, as to be nauseous to the taste. The 

 same was observed, though in a less remarkable degree, of 

 the little tributary we had followed up to our encampment. 

 After leaving the region of red sandstone, we found the 

 water perceptibly purer. In the districts occupied by that 

 rock, we have observed several copious springs, but not 

 one whose waters were without a very manifest impregnation 

 of muriate of soda, or other saline substances. In the gray, 

 or argillaceous sandstone, springs are less frequent, but the 

 water is not so universally impure. 



A beautiful Dalea, two or three Euphorbias, with several 

 species of Eriogonum, are among the plants collected about 

 this encampment. Notwithstanding the barrenness of the sou, 



VOL. II. 10 



