The secret of Hill's striking success with his Western extension was the method by which the line was constructed. Hill had a theory that it was far better to go around mountains and avoid grades than to climb them or to bore through them; it was always better to find the route which would make long hauls easy and economical. He thus built his road with the idea of keeping down the operating costs and of showing a larger margin of profit than the others. From the very start the Great Northern was noted for its low ratio of operating expenses and its comparatively long trains and heavy trainloads. It was by this method that it really made its money. By the year 1901 the Great Northern Railway absolutely controlled its own territory. But it was still handicapped by lack of an independent entrance into Chicago, as its eastern lines terminated at Duluth and St. Paul. At the western end also, the situation was unsatisfactory. It seemed important for the Great Northern to control a line of its own into Portland, Oregon, because the Northern Pacific Railroad, which, as we have seen, had been reorganized several years before by the Morgan interests, had been rapidly extending its lines in Oregon and Washington. Hill and his associates, therefore, had been quietly buying a substantial interest in the Northern Pacific property and thus, in the course of time, had come into closer relations with the Morgan group in New York. Soon afterward, under Hill's influence, the Northern Pacific began the construction of further extensions in Oregon and reached into territory that the Harriman interests in the Union Pacific Railroad had regarded as their own. This move created much friction between the Harriman and Hill groups, and in order to forestall danger Harriman in turn began quietly accumulating an interest in the Northern Pacific property by purchases in the open market.