REPORT ON OREGON TERRITORY 275 RIVERS. The Columbia claims the first notice. Its northern branch takes its rise in the Rocky Mountains in latitude 50 north longitude 116 west; from thence it pursues a northern route to near McGillivary's Pass through the Rocky Mountains. At the boat encampment it is 2,300 feet above the level of the sea, where it receives two small tributaries the Canoe River and that from the Committee's Punch Bowl; from thence it turns south, having some obstruction through its safe navigation, and receiving many tributaries in its course to Colville, among which are the Kootanie, or Flat Bow, and the Flat Head, or Clarke River, from the east, and that of Colville from the west. It is bounded in all its course by a range of high mountains, well wooded, and in places expands into a line of lakes before it reaches Colville, where it is 2,200 feet above the level of the sea, having a fall of a little over 100 feet in 220 miles. To the south of this it trends to the west, receiving the Spokane River from the east, which is not navigable, and takes its rise in the Lake of Coeur d'Alene. Thence it pursues a westerly course for about 60 miles, receiving several smaller streams, and at its bend to the south it is joined by the Okano- gan, a river that has its source in a line of lakes, affording canoe and boat navigation of considerable extent to the north. The Columbia thence passes to the south until it reaches Walla Walla, or the latitude of 45, a distance of 160 miles, receiving the Piscous, Yakima and Point de Bois, or Entiyate- combe, from the west, which take their rise in the Cascade Range; and also its great southeastern branch, the Saptin, or Lewis, which has its source in the Rocky Mountains near our southern boundary, and brings a large quantity of water to increase its volume. The Lewis is not navigable even for canoes, except in reaches. The rapids are extensive and of frequent occurrence, it general- ly passing between the Rocky Mountain spurs and the Blue Mountains.
