The area to be discussed in this paper is in the immediate vicinity of Snoqualmie pass in the northern Cascades. Snoqualmie pass is in central Washington, about 10 miles north of where the Northern Pacific railroad crosses the range. It is a low pass, less than 3,100 feet above sealevel, and is the only point in the state where the range is crossed by a wagon road. On all sides of the pass, however, rugged peaks rise to elevations of from 5,700 to 6,300 feet. Although the geologist finds that this bold topography prevents rapid progress, while the luxuriant vegetation of the western slope at times presents almost impassable obstacles, yet the rock exposures in the higher parts of the range are such as to furnish conclusive evidence as to their character and relations.
In the summer of 1895 Snoqualmie pass was visited by a United States Geological Survey . . .