providing an avenue of transportation since the earliest days of exploration, has played a very important réle in the development of Yukon Territory and Alaska. As this paper is concerned primarily with transportation within Canadian Territory, descriptions will be confined mainly to that part of the Yukon Waterway within Canada. Yukon River is fed in Canada by five principal tribu- taries, the Lewes, Teslin, Pelly, White, and Stewart Rivers, and by innumerable smaller rivers and streams. Beyond the Yukon-Alaska boundary, the Yukon is joined by Porcupine River, which has its source in Yukon Territory, and by Tanana and Koyukuk Rivers. The name “Yukon” is applied to that part of the river situated below the junction of the Lewes and Pelly Rivers in central Yukon. The Yukon Plateau contains the best known and most developed part of the Territory. It is deeply furrowed by a network of main valleys which are entrenched from 1,000 to 2,000 feet below the main upland surface. The bottoms of these valleys, which spread out in a great branching system, are occupied by rivers which in turn are fed by smaller streams issuing from lesser valleys. The volume of the Yukon is less than that of many rivers of similar length, owing to the semi-arid climate of southern Yukon Territory which it drains. Its heads, rising in the mountains, gather volume quickly, but lose their gradient as they come into the plateau. This loss of gradient, with resultant freedom from rapids, has resulted in the formation of a remarkable system of waterways, which permits the operation of river steamers over a total distance of more than 1,400 miles in Yukon Territory (4). Physical Characteristics of Lewes-Yukon Rivers (5) Lewes River, main tributary of the upper Yukon, rises in Lake Lindeman, a small lake on the northern slope of the Coast Mountains in British Columbia. Lake Lindeman was the head of navigation for many gold-seekers traversing the Chilkoot Pass during the Klondike gold rush of 1897-98. A rough, rapid stream connects this lake with Lake Bennett, 26 miles in length, which extends northeastward across the British Columbia-Yukon boundary. Lake Bennett is connected by a narrow strait with Lake Nares, an extension of Tagish Lake, which lies to the east. On the north side of this strait lies the town of Carcross, an abbreviation of Caribou Crossing, after the great herds of caribou that once used this ford. Tagish Lake, including its extensions, Taku Arm and West Taku Arm, together with Teslin Lake to the east, also should be regarded as principal sources of Lewes River. From the northern end of Tagish Lake, Lewes River flows through a comparatively shallow channel into Marsh Lake, 19 miles in length. From Marsh Lake, the river follows a channel about 200 yards wide to Miles Canyon and the Whitehorse Rapids, below which is situated the Town of Whitehorse—terminus of the White Pass and Yukon Railway from Skagway, and now the head of lower- stream navigation on the Yukon Waterway. From the inception of the Klondike gold rush of 1897-98 to the com- pletion of the railway in 1900, thousands of gold-seekers navigated the river from its source, running the treacherous water of Miles Canyon and Whitehorse Rapids in crude boats and rafts. Before completion of the railway, tramways with wooden rails had been constructed overland from the head of the canyon to the foot of the rapids, and were used extensively for the transportation of boats and baggage. From Whitehorse, the Lewes follows a smooth channel for about 20 miles before entering Lake Laberge, 31 miles in length. Lake Laberge contains dangerous shallows, and buoys placed at the upper and lower ends aid navigation. In the 28-mile stretch below Lake Laberge, the Lewes is narrow, crooked, and swift, and its navigation calls for the exercise of skill and judgment by pilot and engineer. At Hootalinqua, the Lewes is joined by Teslin River, which rises in Teslin Lake, about 100 miles to the southeast. About 30 miles northward the Big Salmon flows into the Lewes, and 35 miles below this junction, the Little Salmon adds its waters. From Little Salmon River to Carmacks, a distance of about 36 miles, the current of the Lewes is probably the gentlest of its entire course. Carmacks, a small settlement on the left bank of the river, is also situated on the Overland Trail, a winter road from White- horse to Dawson. About 25 miles below Carmacks are Five Finger Rapids, one of the difficult and exciting sections of the river route. Here four great boulders or rocky islands split the river into five channels or fingers, of which only that on the extreme right is navigable for steamers. In high water, these islands back the water slightly and cause a swell below them. Six miles ahead, Rink Rapids create a navigation hazard. About 5 miles below Rink Rapids is the settlement of Yukon Crossing, where the Overland Trail crosses from the left to the right bank of the river. Between Rink Rapids and Yukon Crossing is found the first large group of islands which dot the river for miles. At the former settlement of Minto, 25 miles below Yukon Crossing, the Overland Trail leaves the Lewes. A little farther on at a section of the river known as Hell’s Gate, improvements to the channel are continually necessary. Opposite the settlement of Fort Selkirk, which is about 264 miles below Whitehorse, the Lewes is joined by Pelly River, and downstream from this point the river is known as the Yukon. The added flow from the Pelly results in a marked increase in the volume and size of the river. From Fort Selkirk to within a short distance of Dawson, the Yukon contains an almost continuous chain of islands which lie mainly in its central part, flanked by channels on either side. From Fort Selkirk to White River, a distance of 90 miles, the water is clear and the current gentle. White River, as the name implies, is a silt-laden stream which enters from the west. Ten miles below White River the Stewart flows into the Yukon from the east, and farther north, Sixtymile River comes in from the west. About 60 miles below Stewart River, the Klondike, famous for its gold-bearing tributaries, joins the Yukon from [ 107 }