74 GEOLOGICAL SUEVEY OF THE TEREITOEIES. 



forks to be fifteen miles each. As we ascended the high ridge between 

 the East and Middle Forks, we obtained a fine view of the surrounding 

 country. Far to the southwest are fine lofty peaks covered with snow, 

 and rising to the height of 10,000 feet. They form a i3art of the mag- 

 nificent range of mountains that separates the Yellowstone from the 

 sources of the Gallatin. From this high ridge we can look down into 

 the chasm of the Middle Fork, which is carved out of the basalt and 

 basaltic conglomerates to the depth of 500 to 800 feet, with nearly 

 vertical sides. In the sides of this caiion, as well as those of the East 

 Fork, splendid examples of basaltic columns are displayed, as perfect 

 as those of the celebrated Fingal's Cave. They usually appear in regular 

 rows, vertical, five and six sided, but far^more sharply cut than any I 

 have ever seen in the West. Sometimes there are several rows, one 

 above the other, with conglomerate between, usually about fifty feet 

 high. Sometimes, however, these columns are spread out fan-like, as is 

 shown in the figure. (Fig. 22.) 



The top of the canon is about 500 yards from margin to margin, but 

 narrowing down until on the bottom it is not more than forty yards 

 Fig. 22. wide. At one point the water pours 



over a declivity of 300 feet or more, 

 forming a most beautiful cascade. The 

 direct fall is over 100 feet. The con- 

 stant roar of the water was pleasant to 

 the ear, and reminded us most strongly 

 of a train of cars in motion. The pines 

 are A^ery dense, usually of moderate 

 size, and among them are many open 

 spaces, which are covered with stout 

 grass, sometimes with large sage- 

 bushes. Upon the high mountain hills 

 the vegetation is remarkably luxuriant, 

 indicating great fertility of soil. The 

 detritus is usually very thick, and cov- 

 BASALT AT LOW FALLS OH cardiner's RIVER, g^s a grcat portiou of tho surfacc, and 

 this is made up mostly of degraded igneous rocks. Above the falls the 

 rows of vertical columns continue in the walls of the caQon, and they 

 may well be ranked, with great fitness, among the remarkable wonders 

 of this rare wonder-land. The lower portion of the canon is composed 

 of rather coarse igneous rocks, which have a jointage and a style of 

 weathering like granite. 



South of the hot springs we ascended a round dome-like mountain, 

 which rises 2,100 feet above them. From the summit we could look from 

 thirty to fifty miles in every direction. To the north and west of us a 

 group of lofty peaks were very conspicuous — over 10,000 feet above the 

 sea, and covered with huge masses of snow. These peaks form a part 

 of the range that separates the waters of the Gallatin from those of the 

 Yellowstone. Farther on to the southward are the peaks of the head 

 of the Madison, and in the interval one black, undulatory mass of pine, 

 with no point rising over 8,500 feet above the sea. These might be called 

 high plateaus, more or less wavy or rolling, interspersed here and there 

 with beautiful lakes a few hundred yards in diameter ; and here and 

 there a bright-green grassy valley, through which the little streams wind 

 their way to the large rivers. In one of these lakes we saw the greatest 

 abundance of a yellow water-lily like N'uphar advena. On the east side 

 of Gardiner's Canon, and west of the Yellowstone, is a sort of wave- 

 like series of ridges, one after the other, with broad, open, grassy inter- 



