Rocky Mountains, 153 



siate when seen in the sunshine, and this, as we found by 

 examination, does not depend entirely on the great propor- 

 tion of mica it contains, but also, in some degree, on the 

 crystalline structure of the minute particles. Its cement is 

 often argillaceous, and this, as well as the impressions of 

 Strobilaria* and other organic relics we observed in it, induc- 

 ed us to expect the occurrence of coal beds. 



On ascending the hills, from the place of our mid-day en- 

 campment, we found this sandstone at an elevation of about 

 two hundred feet, according to our estimate, from the bed 

 of the river, succeeded by a stratum of limestone of the com- 

 mon compact blue variety, abounding in casts of anomias, 

 encrinites, &c. This rests horizontally on the summits of the 

 hills, and as it disintegrates less rapidly than the sandstone 

 which forms their bases, it is sometimes left projecting in 

 such a manner as to render access impossible. Climbing to 

 the summit of some of the hills near the river, we had the 

 view, towards the south and east, of a wild and mountain- 

 ous region, covered with forests, where, among the bright 

 verdure of the oak, the nyssa, and the castanea pumila^ we 

 distinguished the darker shade of the juniper, and others of 

 the coniferae. 



A little before arriving at the place of our evening en- 

 campment, we observed the track of a man who had passed 

 on foot, and with bare feet, down the river. This we were 

 confident could be no other than the track of our lost inter- 

 preter, Adams. What accident could have deprived him of 

 his mule we were at a loss to conjecture. We found it 

 equally difficult to account for his pushing forward with such 

 perseverance, when he must have had every reason to be- 

 lieve we were behind him. 



2d. The morning was fair, and we commenced our jour- 

 ney by sunrise. At a little distance below our encampment, 

 we passed the mouth of a large tributary from the south, 



•Kuttall, 

 VOL. n. 20 



