160 ROYAL SOCIETY OF CANADA 



In the course of geological work carried on in the southern part of 

 the Interior Plateau of British Columbia, particulai-jy in the years 1888, 

 1889 and 1800. to the west of the region above alluded to, but in similar 

 latitudes, much further evidence of the same kind and possessing a similar 

 signilicance has been found. This, indeed, is so universall}' met with 

 where circumstances favourable to its observation occur, that I will cite 

 onl}- a few of the more notable cases, in a general way, in order, to render 

 its character obvious. 



1. In the angle between the main Thompson Eiver and its north 

 branch, not far from Ivamloops. is a tract of rather low grass-covered hills, 

 forming an excellent cattle range and containing in its hollows many 

 small lakes and ponds without outlet. Several of these are fringed by 

 dead trees, comprising aspen poplars twenty years or more old and a few 

 specimens of yellow jiine forty or fifty yesLra of age. The water was 

 standing about their roots in October, 1888, and it was then estimated that 

 the trees had been dead for five or six years. 



2. The i^oint of open plateau between Stump Lake and Douglas 

 Lake, is somewhat similar in character to the last, though with fewer 

 lakes and ponds. Very clear evidence of the same kind was here seen in 

 a lake about three miles north of Douglas Lake, which is bordered by 

 dead trees at least twenty years of age, together with many large, dead, 

 willow bushes. The state of the dead wood led to the conclusion, as 

 noted at the time, that these had not been killed more than ten or less 

 than five years before. It also a|r|ieared that there was here some evidence 

 to show that the water had, for a year or two, been again decreasing 

 (30th July, 1889). 



H. The Green Timl)er Plateau, with an elevation of about 4,000 feet, 

 situated to the north of Clinton, consists partly of woodland and partly of 

 natural meadows or ])rairies of small size, and is characterized by very 

 numerous lakes and ponds, most of which have no outlets and arc more 

 or less distinctly «aline. Many of these are bordered by zones of dead 

 trees, killed by the ri.se of water in the lakes, as in the former cases. In 

 October, 1889. it was noted that most of the trees appeared to have been 

 dead for two, three or more years, while a few had been killed in the 

 jjreceding year. Also that in these lakes the water had fallen to its old 

 normal level, or nearly so, at the date above mentioned; the decrease 

 from its highest i)oint being in some instances as much as ten feet. 



4. Lake to the east of Eight-mile Creek, in Pass Valley. This lake, 

 without outlet, is again bordered by dead trees, some of which were 

 estimated as being of forty years growth. The roots of these trees were 

 ob.served to be still flooded in October, 1889. although it might be supposed 

 that the water of the lakes generally should in that month be not far from 

 its annual minimum. 



5. One of the little lakes in the vallcn' running northwestward from 

 the head of Okanagan Lake was noted, in October. 1890, as exhibiting a 



