620 DEPARTMENT OF THE INTERIOR 



2 GEORGE V., A. 1912 



even imperfect peneplanation close to baselevel is excluded by the second 

 hypothesis. Messrs. Smith and Calkins, who made a reconnaissance survey 

 of the range in connection with the work of the International Boundary Com- 

 mission, have preferred the first of these two hypotheses, while the present 

 writer is practically forced to favour the second. To avoid repetition, the 

 discussion of the alternative will be postponed until the two western ranges have 

 been considered, for Smith and Calkins have extended the two-cycle hypothesis 

 to the entire Cascade system, and it will be well briefly to review the facts 

 before entering further into the field of theory. 



There are many minor physiographic subjects of interest in connection 

 with these beautiful mountains of the Okanagan range. The land-forms due 

 to glaciation have been briefly treated in the last chapter. Certain physio- 

 graphic processes unusually well illustrated in this range will be considered in the 

 following general discussion of the erosion-cycles represented in the Cordillera. 

 As regards the drainage it may here simply be said that, in this range, it is 

 nearly all superposed through the roofs of batholiths. On a previous page it- 

 was noted that the Pasayten valley may be locally of subsequent nature, but 

 there is doubt even of that one case, while elsewhere in the Boundary belt, 

 there is practically no hint of adjustment. This feature, in a terrane so wonder- 

 fully homogeneous in rock-strength, is, of course, no argument against the 

 two-cycle hypothesis. It is mentioned here, specially to show that the evidence 

 as to the causes of the present stream-courses is extremely small. Beyond 

 recognizing the fact of superposition through the batholithic cover, we can 

 get almost no hint, within the Boundary belt, of this drainage history. 



Hozomeen Range. — The main part of this range is composed of the great 

 monocline of Cretaceous sediments, west of which is the narrow horst of the 

 Hozomeen ridge. The local baselevels are found at the Pasayten with altitude 

 of about 3,900 feet above sea and the Skagit at about 1,700 feet above the same 

 datum level. The higher summits' like Castle Peak at 8,340 feet, and Mt. 

 Hozomeen at 8,020 feet above sealevel, are simply the culminating points on 

 unusually high, steep-sided ridges. The canyons of this maturely dissected 

 mountain-block range in depth from 2,000 feet to 3,500 feet or more. Glacial 

 erosion has done something to sharpen the topography which locally bears true 

 alpine horns, but the general cross-sections of the canyons are for the most 

 part rather typical of water-stream and waste-stream erosion. 



A glance at the geological map shows the fact, already recorded in earlier 

 pages, that Lightning creek and the Skagit river locally follow the outcrops 

 of master-faults. The same is true of the main fork of Chuchuwanten creek, 

 and the parallel valleys immediately to the eastward seem to be located on 

 another strike-fault. A few short, longitudinal branch-valleys draining into 

 Lightning creek have the look of adjusted streams which have followed specially 

 weak zones in the upturned Pasayten argillites. Most of the valleys in the 

 Boundary belt are, however, transverse to the strike of the stratified formations. 

 These valleys seem to represent the somewhat diminished successors of the 

 consequent streams which originally drained the wide monocline and the 



