About a hundred and fifty miles below the junction of Lewis's River, we reached the Great Falls. At the commencement of the pitch, which includes the falls, we landed, and walked down to examine them, and ascertain on which side we could make a portage most easily. From the lower end of the island, where the rapids begin, to the perpendicular fall, is about two miles. Here the river contracts, when the water is low, to a very narrow space; and, with only a short distance of swift water, it makes its plunge twenty feet perpendicularly; after which it rushes on, among volcanic rocks, through a channel four miles in length, and then spreads out into a gentle, broad current. We will interrupt the narrative here to introduce from later travellers some pictures of the remarkable region to which our explorers had now arrived. It was not to be expected that Capts. Lewis and Clarke should have taxed themselves, in their anxious and troubled march, to describe natural wonders, however striking. Lieut. Frémont thus describes this remarkable spot:-- THE DALLES.--"In a few miles we descended to the river, which we reached at one of its highly interesting features, known as the Dalles of the Columbia. The whole volume of the river at this place passes between the walls of a chasm, which has the appearance of having been rent through the basaltic strata which form the valley-rock of the region. At the narrowest place, we found the breadth, by measurement, fifty-eight yards, and the average height of the walls above the water twenty-five feet, forming a trough between the rocks; whence the name, probably applied by a Canadian voyageur." The same scene is described by Theodore Winthrop in his "Canoe and Saddle:"-- "The Dalles of the Columbia, upon which I was now looking, must be studied by the American Dante, whenever he comes, for imagery to construct his Purgatory, if not his Inferno. At Walla-walla, two great rivers, Clarke's and Lewis's, drainers of the continent north and south, unite to form the Columbia. It flows furiously for a hundred and twenty miles westward. When it reaches the dreary region where the outlying ridges of the Cascade chain commence, it finds a great, low surface, paved with enormous polished sheets of basaltic rock. These plates, in French, _dalles_, give the spot its name. The great river, a mile wide not far above, finds but a narrow rift in this pavement for its passage. The rift gradually draws its sides closer, and, at the spot now called the Dalles, subdivides into three mere slits in the sharp-edged rock. At the highest water, there are other minor channels; but generally this continental flood is cribbed and compressed within its three chasms suddenly opening in the level floor, each chasm hardly wider than a leap a hunted fiend might take."