Rocky Mountains. 91 



bearing a few cedar bushes, probably the habitation of birds 

 only. 



Leaving this we passed three others in succession, similar 

 in character, but more elevated and remarkable. 



After passing the last of these, the hills ceased abruptly, 

 and we found ourselves once more entering on a vast unva- 

 ried plain of sand. The bed of the creek had become much 

 wider, but its water had disappeared. Meeting at length with 

 a stagnant pool, we halted to dine, but found the water more 

 bitter and nauseous to the taste, than that df the ocean, as 

 it could neither be used for cooking or to drink; we made 

 but a short halt, dining on a scanty allowance of roasted ve- 

 nison, which we ate without bread, salt, water, or any thing 

 else. Some fragments of amygdaloid, were strewed along 

 the bed of the stream, but we saw no more of that rock, or 

 of the other members of the FloetzTrap formation in place. 

 They may extend far towards the southwest, but of this we 

 have no conclusive evidence. The aspect of these rocks par- 

 ticularly of the amygdaloid or toad -stone, is so peculiar, and 

 its disposition so remarkably dissimilar to that of the sand- 

 stones, with which it is associated, as strongly to suggest the 

 idea of a different origin. 



In the midst of one of the violent storms, we encountered 

 in passing this trap formation, we crossed the point of along 

 but low ridge of amygdaloid, so singularly disposed as to 

 suggest to every one of the party, the idea, that the mass 

 had once been in a fluid state, and that when in that state it 

 had formed a current, descending along the bed of a narrow 

 ravine, which it now occupied, conforming to all the sinu- 

 osities and inequalities of the valley, as a column of semi- 

 fluid matter would do. Its substance was penetrated with 

 numerous vessicular cavities, which appeared in some in- 

 stances elongated in the direction of the ridge. Its colour is 

 nearly black; and when two masses are rubbed together, they 

 emit a smell somewhat like the soot of a chimnev. These 



