The so-called canon of the Salmon River lies just above the twin glaciers. Scenically, these are by far the more impressive, and they present a more complex engineering problem; yet the canon itself was the real strategic point in the struggle between the railroad-builders. The floor of the valley immediately above Garfield glacier, though several miles wide, was partly filled with detritus which had been carried down from the mother range on the east, and this mass of debris had forced the stream far over against the westward rim, where it came roaring past the foot wall in a splendid cataract some three miles long. To the left of the river, looking up-stream at this point, the mountains slanted skyward like a roof, until lost in the hurrying scud four thousand feet above. To the right, however, was the old moraine, just mentioned, consisting of a desolate jumble of rock and gravel and silt overlaying the ice foot. On account of its broken character and the unstable nature of its foundation this bank was practically useless for road-building, and the only feasible route for steel rails was along the steep west wall. O'Neil on his first reconnaissance had perceived that while there was room for more than one bridge across the Salmon between the upper and the lower ice masses, there was not room for more than one track alongside the rapids, some miles above that point. He knew, moreover, that once he had established his title to a right-of-way along the west rim of the cataract, it would be difficult for a rival to oust him, or to parallel his line without first crossing back to the east bank--an undertaking at once hazardous and costly. He had accordingly given Dan Appleton explicit instructions to be very careful in filing his survey, that no opportunity might be left open for a later arrival. The engineer had done his work well, and O'Neil rested secure in the belief that he held possession of the best and least expensive route through to the open valleys above. He had had no cause to fear a clash with the Heidlemann forces, for they had shown a strict regard for his rights and seemed content to devote themselves to developing their terminus before trying to negotiate the canon. They were wise in taking this course, for their success would mean that O'Neil's project would fall of its own weight. Kyak was nearer Seattle, by many miles, than Omar; it was closer to the coal and copper fields, and the proven permanence of their breakwater would render useless further attempts to finance the S. R. & N.