After going down the Bitter Root for a short distance they turned west again across the Bitter Root Mountains and came out upon the head waters of the Kooskooskie River. Unable to follow its canons, they wandered to the north among the mountains. At this time their sufferings were intense. Food became so scarce that they were obliged to eat their horses. After many weary days they again reached the stream, but this time at a point where it was navigable. They floated down to its junction with the Lewis or Snake River, where the growing city of Lewiston now stands. At this point they met the Nez Perces Indians, who assisted them in every possible way. [Illustration: FIG. 69.--CELILO FALLS, COLUMBIA RIVER] The party continued down the Snake River in canoes until they finally reached the Columbia. The difficulties of navigation were great, for at intervals of every few miles the river was broken by rapids through which it was dangerous to take the canoes. By treating the Indians kindly, the party succeeded in trading with them for such articles of food as horses and dogs. They also obtained some salmon. The presence of this fish in the streams gave them the first assurance that the Pacific slope had been reached. Along the Columbia River salmon was one of the chief articles of food for the Indians. At Celilo Falls, a short distance above the present city of The Dalles, the travellers found great difficulty in proceeding, as the canoes and loads had to be carried, or "portaged," around the falls. Lewis and Clark called these the Great Falls of the Columbia (Fig. 69). As the canoes floated down through the magnificent canon by which the Columbia passes the Cascade Range, they encountered another rapid, now known as the Cascades of the Columbia. This rapid is due to a great landslide which has formed a dam across the river. Captain Lewis speaks of the broken trunks of trees rising from the water above the dam, a fact which would lead one to suppose that it had not been very long since the slide occurred. Below the Cascades the party soon began to notice the influence of the tides in the rise and fall of the river, and knew then that the Pacific could not be very far away. Early in November they came in sight of the ocean, and in a few days had the pleasure of standing upon its shores. The long and dangerous trip of four thousand miles had been completed without any serious accident. Continual rains poured upon them, and before winter quarters could be prepared they were in a very uncomfortable position. A permanent camp was selected upon the Oregon side of the Columbia, and log buildings were erected. The camp was called Fort Clatsop. While in their winter quarters the party cultivated friendly relations with the Indians, and made extensive notes upon their habits and characteristics. [Illustration: FIG. 70.--THE CASCADES OF THE COLUMBIA A steamer going up to the locks]