The lower reaches of the valley of Gardiner's River, and the enclosing hillsides, are strewn with volcanic rock, having the appearance of furnace cinder. The tops of the rounded hills are covered with fragments of basalt and conglomerate, whose great variety of sombre colors add much to the appearance of desolation which characterizes the valley. Here and there are stagnant lakes fifty to a hundred yards in diameter, apparently occupying ancient volcanic vents. Crossing a barren, elevated region two miles in extent, and three or four hundred feet above the river-bed, the trail descends abruptly to a low "bottom" covered with a thick calcareous crust, deposited from hot springs, now for the most part dry. At one point, however, a large stream of hot water, six feet wide and two feet deep, flows swiftly from beneath the crust, its exposed portion clearly revealed by rising steam. The quantity of water flowing from this spring is greater than from any other in this region; its temperature ranges from 126° to 132° Fah. A little further above are three or four other springs near the margin of the river. These have nearly circular basins, six to ten feet in diameter, and a temperature not above 120°. Already these springs have become the resort of invalids, who speak highly of the virtues of the waters. A short distance up the hill are abundant remains of springs, which in time past must have been very active. For nearly a mile the steep hill-side is covered with a thick crust of spring deposits, which, though much decomposed and overgrown with pines and cedars, still bear traces of the wonderful forms displayed in the vicinity of the active springs further up the hill. Ascending the hill, Dr. Hayden's party came suddenly and unexpectedly upon these marvellous deposits, which they agreed in pronouncing one of the finest displays of natural architecture in the world. The snowy whiteness of the deposit, which has the form of a frozen cascade, at once suggested the name of White Mountain Hot Spring. The springs now in active operation cover an area of about one square mile, while the rest of the territory, three or four square miles in extent, is occupied by the remains of springs which have ceased to flow. Small streams flow down the sides of the Snowy Mountain in channels lined with oxide of iron of the most delicate tints of red. Others show exquisite shades of yellow, from a deep, bright sulphur, to a dainty cream-color. Still others are stained with shades of green, all these colors as brilliant as the brightest aniline dyes. The water after rising from the spring basin flows down the sides of the declivity, step by step, from one reservoir to another, at each one of them losing a portion of its heat, until it becomes as cool as spring-water. Within five hundred feet of its source Dr. Hayden's party camped for two days by the side of the little stream formed by the aggregated waters of these hot springs, and found the