Before that time the St Paul had been a great local railway, operating primarily in the Dakotas, Minnesota, Iowa, Wisconsin and Illinois; but by the construction of a long arm from the Missouri river to Spokane, Seattle and Tacoma, it became a transcontinental line of the first importance, avoiding the mistakes of earlier railway builders by securing a line with easy gradients through the most favourable regions.
It is served by the Northern Pacific, the Great Northern, the Oregon & Washington, and the Spokane, Portland & Seattle railways, and by steamship lines, being accessible to sea-going vessels; a ferry connects with the Portland Electric railway.
East of the Cascade Mountains the Columbia and Spokane rivers mark the boundary between the Okanogan Highlands to the northward and the Columbia plateau to the southward; The Okanogan Highlands, an outlier of the Rocky Mountains extending westward from the Coeur d'Alene Mountains in Idaho, reach heights of 5000 to 6000 ft.
Tungsten is found as wolframite in Stevens county near Deer Trail and Bissell, in Okanogan county near Loomis, in Whatcom county near the international boundary, and (with some scheelite) at Silver Hill, near Spokane.
The Northern Pacific and the Great Northern enter the state near the middle of its eastern boundary at Spokane, which is a centre for practically all the railway lines in the eastern part of the state.
