The total extent of the cataract at the Cascades is five miles and the descent is about forty-five feet, of which half is at the upper end at the point passed by the locks. We enter the locks in the wake of one of the steamers, and in a few minutes find our craft emerging from the lower end of the massive structure into the white water which bears us swiftly down the remaining part of the Cascades. It looks dangerous to commit an open boat to that sweeping current, but as a matter of fact the course of the river is straight and deep, though swift, and it is entirely feasible for any one of reasonable skill to manage a small boat in the passageway to the tranquil expanses below. [Illustration: Horseshoe Basin, near Lake Chelan, Wash. Photo. by T. W. Tolman, Spokane.] As we speed swiftly down the river, we note the little station of Bonneville, named for the historic fur-trader whom the fascinating pages of Irving have brought down to this era. A short distance below Bonneville our eyes catch sight of a white sign-board bearing the words, "Petrified Tree." Sure enough, there is the tree, and a marvellously fine specimen of silicification it is, too. When the railroad was built along the river bank at this point, the graders ran into a perfect forest of petrified wood. The logs and limbs were piled up by the cord near Bonneville, but the larger part has been taken in various directions for cabinets and ornaments. But a short time is needed to fly down the Cascades, and at their lower end we reach what may be called the Lower River. For here a slight rise and fall of tide betokens the presence of the ocean. No more rapids on the River, but a tranquil, majestic flood, broadening like a sea toward its final destination, a hundred and sixty miles away. If we were to describe in detail all the marvels of beauty and grandeur and physical interest which engage our attention at every stage of the journey, our volume would end with this chapter, for there would be no room for anything more. One class of objects of curious interest to almost all travellers, though of no special charm to scientist or nature lover, is the fish-wheels at the Cascades. These are very ingenious contrivances set in the midst of a swift place in the stream and made to revolve by the current. As they revolve, the huge vans dipping the water scoop up almost incredible numbers of the salmon which have made the Columbia famous the world over. A weir is built to turn the fish from the outside course into the channel of the wheel, with the result that numbers are taken almost beyond belief, sometimes as high as eight tons a day by a single wheel. Another picturesque sight, both at the Celilo Falls and the Cascades, is the Indian fishermen perched upon the rocks and with spear and dip-net seeking to fill their larder with the noble salmon.