80 GEOLOGICAL SLTIVEY OF THE TEEEITOEIES. 



The view from the summit of Mount Washburn is one of the finest I 

 have ever seen, and although the atmosphere was somewhat obscured by 

 smoke, yet an area of fifty to one hundred miles radius in every direction 

 could be seen more or less distinctly. We caught the first glimpse of the 

 great basin of the Yellowstone, with the lake, which reminded one much, 

 &om its bays, indentations, and surrounding mountains, of Great Salt 

 Lake. To the south are the Tetons, risin g high above all the rest, the mon- 

 archs of all they survey, with their summits covered with perpetual snow. 

 To the southwest an immense area of dense pine forests extends for one 

 hundred miles without a peak rising above the black, level mass. A lit- 

 tle farther to the southwest and west are the Madison Mountains, a lofty, 

 gTand, snow-capped range, extending far to the northward. Kearer and 

 in full view, to the west commence the bold peaks of the Gallatin Range, 

 extending northward as far as the eye can reach. To the north we 

 get a full view of the valley of the Yellowstone, with the lofty ranges 

 that wall it in. EmigTant Peak, and the spleudid group of moun- 

 tains of which it is a part, can be clearly seen, and lose none of their 

 marvelous beauty of outline, view them from what point we may. To 

 the north and east the eye scans the most remarkable chaotic mass of 

 peaks of the most rugged character, apparently without system, yet 

 sending their jagged summits high up among the clouds. Farther dis- 

 tant are somewhat more regular ranges, snow-covered, i)robably the 

 Big Horn. But with all this magnificent scenery around us from every 

 side, the greatest beauty was the lake, in full view to the southeast, 

 set like a gem amid the high mountains, which are literally bristling 

 with peaks, many of them capped with snow. These are all of volcanic 

 origin, and the fantastic shapes which many of them have assumed 

 under the hand of time, called forth a variety of names from my party. 

 There were two of them that represented the human profile so well that 

 we called them the "Giant's Face" and "Old Man of the Mountain.'^ 

 These formed good landmarks for the topographer, for they were visible 

 from every i)oint of the basin. 



Mount Washburn is composed entirely of the usual igneous rocks. 

 On the summits are i)iles of very hard, com])act basalt, cleaving into 

 laminae, or in irregular blocks. AH around on the sides of the mountain 

 are immense accumulations of the usual volcanic breccia. The central 

 mass was originally a volcanic cone, building up a crater with the com- 

 pact basalt, but throwing out in the surrounding or enveloping waters 

 the fragments or dust which were cemented together all around on the 

 sides, sometimes reaching very nearly to the summit. On the southeast 

 side of the mountain a distinct anticlinal interval or opening is seen in 

 the breccia. The south side inclines east 25^, and breaks off abruptly 

 near the Grand Canon, while the opposite side dips west 20^. Between 

 this anticlinal and the caiion there is a bench five hundred feet below the 

 summit of the mountain, which, I am convinced, formed the inner por- 

 tions of the old crater, while the breccia composed the outer walls. To 

 the southeast there is a grassy plateau ten to twenty miles in extent, 

 immediately surrounded with dense forests of pine. We may say, in 

 brief, that the entire basin of the Yellowstone is volcanic. I am not 

 prepared to i)ronounce it a crater, with a lake occupying the inner por- 

 tion, while the mountains that surround the basin are the ruins of this 

 great crater j but, at a period not very remote in the geological past, 

 this whole country was a scene of wonderful volcanic activity. I regard 

 the hot springs so abundant all over the valley as the last stages of this 

 grand scene. Hot springs, geysers, &c., are so intimately connected 

 with what we usually term volcanoes that their origin and action 



