Many of the capricious formations wrought from the shale excite merriment as well as wonder. Of this kind especially was a huge mass sixty feet in height, which, from its supposed resemblance to the proverbial foot of his Satanic Majesty, we called the "Devil's Hoof." The scenery of mountain, rock, and forest surrounding the falls is very beautiful. Here, too, the hunter and fisherman can indulge their tastes with the certainty of ample reward. As a half-way resort to the greater wonders still farther up the marvellous river, the visitor of future years will find no more delightful resting-place. The name of "Tower Falls," which we gave it, was suggested by some of the most conspicuous features of the scenery." [Illustration: THE DEVIL'S HOOF.] The sides of the chasm are worn into caverns lined with variously-tinted mosses, nourished by clouds of spray which rise from the cataract; while above, and to the left, a spur from the great plateau rises over all, with a perpendicular front of 400 feet. The fall is accessible both at the brink and at the foot, and fine views can be obtained from either side of the cañon. In appearance it strongly resembles Minnehaha, but is several times as high, and the volume of water is at least eight times as great. In the basin a large petrified log was found imbedded in the débris. "Nothing," says Lieutenant Doane, "can be more chastely beautiful than this lovely cascade, hidden away in the dim light of overshadowing rocks and woods, its very voice hushed to a low murmur, unheard at the distance of a few hundred yards. Thousands might pass by within a half mile and not dream of its existence; but once seen, it passes to the list of most pleasant memories." Along the Yellowstone, near the mouth of Tower Creek, is a system of small mineral springs distributed for a distance of two miles in the bottom of the deep cañon through which the river runs. Several of these springs have a temperature at the boiling point; many are highly sulphurous, holding, in fact, more sulphur than they can carry in solution, and depositing it in yellowish beds along their courses. Several of them are impregnated with iron, alum, and other substances. Their sulphurous fumes can be detected at the distance of half a mile. The excess of sulphur in the rock-walls of the cañon give a brilliant yellow color to the rocks in many places. The formation is usually very friable, falling with a natural slope to the edge of the stream, but occasionally masses of a more solid nature project from the wall in curious shapes of towers, minarets, and the like; while over all the solid ledge of trap, with its dark and well-defined columns, makes a rich and beautiful border inclosing the pictured rocks below. This is the mouth of the Grand Cañon of the Yellowstone. CHAPTER VII. OVER MOUNT WASHBURN TO THE FALLS OF THE YELLOWSTONE.