South of the hot springs is a round dome-like mountain, rising 2,100 feet above them, or 8,500 feet above the sea. Its summit commands a prospect from thirty to fifty miles in every direction. To the north and west stands a group of lofty peaks 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 mass of pine forest, covering high plateaus, with no point rising over 8,500 feet above the sea--the whole region being 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 little streams wind their way to the large rivers. In one of these lakes the explorers saw the greatest abundance of yellow water-lily, which blooms in great profusion on the surface of all the mountain lakes of the Yellowstone Basin. On the east side of Gardiner's Cañon, and west of the Yellowstone, is a sort of wave-like series of ridges, with broad, open, grassy interspaces, with many groves of pines. These ridges gradually slope down to the Yellowstone, northeast. Far to the east and north is one jagged mass of volcanic peaks, some of them snow-clad, others bald and desolate to the eye. Far to the south, dimly outlined on the horizon, may be seen the three Tetons and Madison Peak--monarchs of all the region. A grander view could not well be conceived. Leaving Gardiner's River, Dr. Hayden's party ascended the broad slope of the dividing ridge between that river and the streamlets which flow into the Yellowstone. Immense boulders of massive granite, considerably rounded, are a marked feature of the country about the entrance of the East Fork. One of these, a mass of red feldspathic granite, is twenty-five feet thick and fifty feet long. The high wavy ridge, 9,000 feet above the sea, is composed of beds of steel-gray and brown sandstone and calcareous clay, in which are numerous impressions of deciduous leaves. Vast quantities of silicified wood of great perfection and beauty are scattered all over the surface. In some cases long trees have been turned to agate, the rings of growth as perfectly shown as in recent wood. The soil is very thick, and covered with luxuriant vegetation. "We were travelling through this region in the latter part of the month of July," writes Dr. Hayden, "and all the vegetation seemed to be in the height of its growth and beauty. The meadows were covered densely with grass and flowers of many varieties, and among the pines were charming groves of poplars, contrasting strongly by their peculiar enlivening foliage with the sombre hue of the pines. The climate was perfect, and in the midst of some of the most remarkable scenery in the world, every hour of our march only increased our enthusiasm.