The Upper or Grand Cañon of the Yellowstone extends from the mouth of Tower Creek to the foot of the Great Fall, a distance of twenty miles. It is impassable throughout its entire length, and accessible to the water's edge only at few points and by dint of severe labor. The trail ascends the divide between Tower Creek and the Yellowstone, skirting for six or eight miles the cañon of Tower Creek. The ground rises rapidly and is much broken by creek-beds running parallel with the river. Following the highest ridges, the first explorers reached at last a point whence they could overlook the Grand Cañon cleaving the slopes and breaking through the lofty mountain ranges in front. Here they caught their first glimpse of a phenomenon afterwards to become a familiar sight to them. Through the mountain gap formed by the cañon, and on the interior slopes some twenty miles distant, an object appeared which drew a simultaneous expression of wonder from every one in the party. It was a column of steam, rising from the dense woods to the height of several hundred feet. They had all heard fabulous stories of this region, and were somewhat skeptical of appearances. At first it was pronounced a fire in the woods, but presently some one noticed that the vapor rose in regular puffs, as if expelled with a great force. Then conviction was forced upon them. It was, indeed, a great column of steam, puffing away on the lofty mountain side, with a roaring sound, audible at a long distance, even through the heavy forest. A hearty cheer rang out at this discovery, and they pressed onward with renewed enthusiasm. The highest peak of this ridge was named by the first company who climbed it--Mount Washburn--in honor of their leader. The view from its summit is "grand beyond description;" yet some conception of its grandeur can be formed, let us hope, from the graphic review of its more striking features by Lieutenant Doane.