On the 13th April the mouth of the Little Missouri was passed, and on the 26th that of the rapid Yellowstone River, from Sublette’s Lake in the Rocky Mountains. From this great landmark the course of the Missouri――and, as a result, of the explorers――was due west, and the character, alike of the scenery, the fauna, and the flora, changed perceptibly. In the journals from which our narrative is culled, we find notes on the strange appearance presented by banks and sandbars covered with salt, looking like frost; on the white and red “bluffs,” probably rich in minerals, on either side of the stream; and most interesting of all, on meetings of frequent occurrence with white or brown bears. On more than one occasion, Captain Lewis almost lost his life in encounters with these formidable creatures. His first escape was from a white bear, one of two which suddenly appeared in his path when he was on shore with only one hunter, and which, though badly wounded, pursued him for a long distance. On another occasion Lewis went in pursuit of a brown bear, which had been wounded by some of his men, and found the poor creature lying in a kind of bed in the earth, two feet deep and five feet long, which he had scooped out for himself after receiving his death blow. Lewis put an end to his agonies by firing through his skull, and in his account of the matter he speaks in terms of high admiration of the courage and intelligence displayed by all the brown bears he had opportunities of watching. In the different journals kept by various members of this great expedition, our readers who love sporting adventures will find many another fascinating anecdote of a similar kind to the two we have selected; but, with our heroes, we must press on for the West, pausing, as they did, on the 3d of June, 1805, at a spot some miles above the mouth of the Yellowstone, where the Missouri divides into two great channels, or forks, as they are called in America. Thus far, all had been successful. The course of the Missouri had been carefully traced, and something had been learned of that of every great tributary; but now a mistake would be fatal. From what the natives said, the leaders of the expedition were convinced that one of these two channels led to the sources, not only of the Missouri, but also of the Columbia, that great river of the West first, as we believe, discovered by Viscaino in 1602, though the honor due to him has been given to a certain Captain Gray, of Boston, who, in 1792, entered the mouth of the mighty stream when on a trading expedition, and gave it the name it still retains, after his own vessel.