Rocky Mountains. 13 



Second — Fine compact gray sandstone, containing a few 

 impressions of organic remains, resembling those in the 

 sandstones of coal formations. This rock is inclined at an 

 angle of near twenty degrees towards the west. It forms 

 continuous ranges of hills, not difficult of ascent from the 

 east, bat their western declivities are abrupt and precipitous. 



Third — Lofty and detached columns of sandstone of a 

 reddish or deep brown colour. These are irregularly scatter- 

 ed throughout a narrow woodless valley. Some of them rise 

 probably three hundred feet above the common level of the 

 plain, and are so steep on all sides as to preclude the possi- 

 bility of ascent; others are accessible at some points, and 

 one of these we ascended. 



Fourth — Coarse white pudding-stone, or conglomerate 

 and sandstone of a deep red colour, alternating with each 

 other, and with beds of fine white sandstone, and resting 

 against the granite in a highly inclined position. This rock 

 contains well preserved remains of terebratula, productus, 

 and other bivalve shells. These are usually found on or 

 near the surface of large nodules of a fine flinty stone, close- 

 ly resembling petrosilex. The same rock also contains an 

 extensive bed of iron ore, and from its eastern side flows a 

 copious brine spring. 



About this spring, which had evidently been much fre- 

 quented by animals, we saw the skulls of the male and female 

 Big horn;* the bones of elk, bisons, and other animals. 



The granite, which succeeds the sandstone last mentioned, 

 is of a dark reddish-brown colour, containing a large pro- 

 portion of feldspar of the flesh coloured variety, and black 

 mica. The crystalline grains or fragments of the feldspar 



* Big-horn. This animal has been rudel}' figured by Venegas on his 

 second plate, who informs us that it is known to the natives of California 

 by the name of Taye; another figure, but also a bad one, was given by Mr. 

 Geoffroy in the Ann. de Museum, und»T the name of Ovis montana 



Two specimens, a male and female, were taken to Philadelphia by Lew- 

 is and Clark, which are set up in the museum of that city. 



