[Illustration:  HEAD OF ROCKY MOUNTAIN WILD SHEEP.]

The gray, boulder-chafed river was singing loudly through the valley, but above its massy roar I heard the booming of a waterfall, which drew me eagerly on; and just as I emerged from the tangled groves and brier-thickets at the head of the valley, the main fork of the river came in sight, falling fresh from its glacier fountains in a snowy cascade, between granite walls 2000 feet high.  The steep incline down which the glad waters thundered seemed to bar all farther progress.  It was not long, however, before I discovered a crooked seam in the rock, by which I was enabled to climb to the edge of a terrace that crosses the canon, and divides the cataract nearly in the middle.  Here I sat down to take breath and make some entries in my note-book, taking advantage, at the same time, of my elevated position above the trees to gaze back over the valley into the heart of the noble landscape, little knowing the while what neighbors were near.

After spending a few minutes in this way, I chanced to look across the fall, and there stood three sheep quietly observing me.  Never did the sudden appearance of a mountain, or fall, or human friend more forcibly seize and rivet my attention.  Anxiety to observe accurately held me perfectly still.  Eagerly I marked the flowing undulations of their firm, braided muscles, their strong legs, ears, eyes, heads, their graceful rounded necks, the color of their hair, and the bold, upsweeping curves of their noble horns.  When they moved I watched every gesture, while they, in no wise disconcerted either by my attention or by the tumultuous roar of the water, advanced deliberately alongside the rapids, between the two divisions of the cataract, turning now and then to look at me.  Presently they came to a steep, ice-burnished acclivity, which they ascended by a succession of quick, short, stiff-legged leaps, reaching the top without a struggle.  This was the most startling feat of mountaineering I had ever witnessed, and, considering only the mechanics of the thing, my astonishment could hardly have been greater had they displayed wings and taken to flight.  “Surefooted” mules on such ground would have fallen and rolled like loosened boulders.  Many a time, where the slopes are far lower, I have been compelled to take off my shoes and stockings, tie them to my belt, and creep barefooted, with the utmost caution.  No wonder then, that I watched the progress of these animal mountaineers with keen sympathy, and exulted in the boundless sufficiency of wild nature displayed in their invention, construction, and keeping.  A few minutes later I caught sight of a dozen more in one band, near the foot of the upper fall.  They were standing on the same side of the river with me, only twenty-five or thirty yards away, looking as unworn and perfect as if created on the spot.  It appeared by their tracks, which I had seen in the Little Yosemite, and by their present position, that when I came up the canon they were all feeding together down in the valley, and in their haste to reach high ground, where they could look about them to ascertain the nature of the strange disturbance, they were divided, three ascending on one side the river, the rest on the other.