218 



GEOLOGICAL SUJKVEY OF THE TERRITORIES. 



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tinct peaks in the range ; but those upon its northern and southern por- 

 tions are uoinewhat lower than the central 

 ones, and have more of the high western 

 parts of the range opposite to them, so that 

 they are mostly hidden in that direction 

 until we approach quite closely. 



The following section, (Fig. 4G,) though 

 the elevations are somewhat exaggerated, 

 will give a good general idea of the country 

 thus passed through in coming from Henry's 

 Fork to the crest of the T6ton range. The 

 broad, gradually-rising, high terrace of ba- 

 salt and trachytes, cut by the deep cations 

 of Pierre's and other rivers, breaks down 

 into the rounded depression of Pierre's Hole, 

 whence the slopes of porphyries rise more 

 rapidly to the still steeper outcrops of the 

 Carboniferous and other limestones. 



These, again, are cut by the deep canons 

 of West Teton Creek and others of similar 

 character, some of which slightly expose 

 the granite, while some do not. Between 

 this western drainage {I) and the Great 

 Caiion, [m,) which breaks through the range 

 to the eastward, there is, in some cases, a 

 block of limestones as here represented, 

 while, in others, the divide is entirely of 

 metamorphic rocks. Finally reaching the 

 crests, we look down, over clean sheer gran- 

 ite-walls, to the broad sage-covered plain of 

 Jackson's Hole, bordered on the other side 

 with the rolling foot-hills of the main range 

 of the Eocky Mountains. 



We had postponed our attempt upon the 

 highest peak until we could make it under 

 the most favorable circumstances, and 

 Messrs. Stevenson and Langford had made 

 some preliminary examinations, so as to 

 select the best route. Soon after sunrise, 

 on July 29, from a temporary camp previ- 

 ously formed at the nearest convenient 

 point, in the right-hand fork of the caiion of 

 West Teton Creek, we started for the sum- 

 mit. Cold streams fall in beautiful cascades, 

 for from 200 to 300 feet, over the caiion -wall 

 '*■ ^° on our left. Climbing over piles of loose 

 debris, from the deep cavities of which we 

 heard the frequent kid-like bleat of the rare 

 little coney, Lagomys princeps, so seldom 

 seen, and over rock-slopes nearly as steep 

 as any we saw that day, we reached the top 

 of the cliff and found a broad valley, leading 

 from the very verge of the caiion-wall di- 

 rectly toward the peak, bounded on either 

 side by more or less precipitous waHs of 

 Quebec Group limestone, above which ap- 

 peared some isolated patches of the bed which we have referred to the 



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