GEOLOGICAL SURVEY OF THE TERRITORIES. 215 



the scene, in 1832, of a sharp figbt with Blackfoot Indians, which is 

 vividly described by Irving in his Bonneville's Adventures. In his 

 description of that battle the woods are said to have been " tangled 

 with vines." On the other hand, the entire absence of every kind of 

 vines from all this region, with the exception of scattered plants of GUma- 

 i^is along the banks of ditches and creeks, isoneof the notable features 

 along the whole length of our route. It is reported that vines grow 

 luxuriantly on some of the islands in the Yellowstone Lake. 



The extreme northeastern angle of this basin is occupied by a shallow 

 pond about live hundred yards in diameter, with marshy borders, whose 

 surface was covered with tracks of antelope, deer, and elk. This pond 

 is supplied by springs bursting out at the base of the surrounding foot- 

 hills. One of these, of the temperature of 45°, is about 50 feet across 

 and throws out a rapid stream 10 feet wide and 1 foot deep, with a clean 

 bottom of fine volcanic; sand. The water evidently comes from the rap- 

 idly melting banks of snow upon the moutains, and finds its way by 

 subterranean channels through the porous volcanic rocks of the lower 

 slopes. 



Crossing this basin, we at length camped, on July 23, in the mouth af 

 the canon of the largest tributary of Pierre's Eiver, which is known as 

 T6ton Creek, or BigTeton Creek, because it heads directly toward the high- 

 est Teton and its valley gives a tine view of that peak. Though it heads 

 in the very center of the range, still it does not gather the drainage of the 

 T^ton peaks themselves, but that escapes into a stream called T^ton 

 Eiver, which flows to the east and joins the Snake Eiver in Jackson's 

 Hole. Under the circumstances, we can hardly displace either name, 

 and must be satisfied to distinguish them by the use of the adjectived 

 titles East and West. 



The valley which Ave now entered is wider than those of the other trib- 

 utaries of Pierre's Eiver, and, unlike them, has a broad tongue of th« 

 prairie running up it for two or three miles, so that good camping- 

 places can be found with abundant pasture for the stock, while steep 

 slopes on either side will check their propensity to stray. It had, there- 

 fore, been selected for the location of a permanent camp, while small 

 parties were going out in various directions to explore the neighborhood. 



The lower slopes of the foot-hills of the range, up to a height of from 

 400 to 500 feet above the plain, consist of variously-colored porphyries, 

 representing the extreme edge of the great volcanie district, which had 

 become so wearisome to us by reason of its sameness. Though the line 

 of junction with the older rocks was not found, yet these latter outcrop 

 at such points as to show that the porphyries were deposited against 

 originally steep slopes. I did not succeed in finding any beds of por- 

 phyry so tilted as to indicate any modern continuance of the upheaval 

 of which the older rocks give abundant evidence. 



From beneath the upper edges of the porphyries emerge first about 

 2,000 feet of compact, often quite cherty, gray to drab Carboniferous 

 limestones, mostly rather barren of fossils, except a few of the lower 

 layers, which are crowded with Zajihrentis, Cyathaxonia, Syringopora, 

 Froductus, Spirifer, and other forms, mostlj' silicified, and so weathering 

 out finely upon the surface of exposed slabs. These beds, however, are 

 but slightly exposed, except on the higher crests : where they appear 

 low down in the canons, they are almost always covered up by the debris 

 of the higher layers. 



Beneath them appear about 600 feet of a heavy-bedded, drab to light- 

 buff vesicular magnesian limestone, entirely destitute of fossils, so far 

 as I could ascertain, except minute fragments of crinoid stems; but, 



