On the upper river the engineers were making extensive preliminary examinations and reconnaissance surveys while it was still the sole channel of transportation for that rapidly developing "Inland Empire." The exceedingly favorable reports of Major Michler, of 1874, of Major Powell, in 1879, and of Lieutenant Symons, in 1881, gave the demand for an "open river" standing in the inner administration circles. This part of the river was already receiving small appropriations for the removal of minor obstructions in the early '70s. On October 12, 1877, the Secretary of War approved the original plan for canal and locks around the rapids in the Columbia, where it passes through the Cascade Mountain range. In thus tackling one of the two formidable obstructions to navigation the national government may be said to have committed itself to the securing of a channel available to navigation throughout this system of inland waterways.
The task with which the national government was confronted in having undertaken to secure to the people of the Pacific Northwest the advantage of inland waterways is probably best indicated by pointing out the obstructions that are, or were, encountered in passing from its mouth to its source. From the ocean up to the mouth of the Willamette, about ninety-eight miles, where the original depth was from ten to fifteen feet, ocean vessels now pass drawing twenty-five feet of water. The improvement was effected mainly through dredging. From the mouth of the Willamette to the "Cascades," about forty-three miles farther up the river, it is open, and in its natural state has an available depth of eight feet. At the "Cascades" for four and onehalf miles it is so contracted in width in passing through mountains that it partakes of the nature of a gorge. In the upper first half mile of this there is a fall of twenty-four feet. Throughout the lower four miles of the gorge the slope is not so steep, but the channel is much obstructed with boulders and reefs. This first great obstruction could be obviated only by a canal and locks. Such works were so far
