PEACE AND ATHABASCA GLACIAL LAKES. 275 



depression of the watershed at the Methy portage probably afforded, as 

 remarked on a foregoing page, the lowest and latest channel of outflow 

 from the Mackenzie basin to Lake Agassiz. 



The watercom'se by which the Churchill, bringing the Peace and 

 Athabasca outflow, passed into the Saskatchewan, tributary to Lake Agas- 

 siz, begins at Frog portage and extends south-southeastward about 100 

 miles by a Lake of the Woods, Pelican, Heron, and Birch lakes. Great 

 and Ridge rivers, Beaver, Sturgeon, and Pine Island lakes, to the Sas- 

 katchewan at Cumberland House. This was the route of Franklin and 

 Richardson in 1820. The latter states that "by Beaver Lake and its chain 

 of waters Nelson River receives supplies from the very banks of the Mis- 

 sinippi or Churchill River. Indeed, the Beaver Lake chain, which lay in 

 our route, originates within a hundred yards of the latter stream." Frog 

 portage, at this locality, "is 380 paces long. The path leads through a low, 

 swampy wood, and over a flat tract of gneiss rising only a few feet above 

 the waters on each side." The further descriptions of their journey up the 

 Churchill, which "resembles a chain of lakes with many arms, more than 

 a river," and by Isle h la Crosse Lake, Deep River, Clear and Bufi'alo lakes, 

 and Methy River and Lake to Methy portage, indicate that this was at one 

 time the avenue of outflow from a glacial lake in the Mackenzie basin. Isle 

 h la Crosse, Clear, and Bufi'alo lakes, which, according to Macoun, have the 

 same level, being stagnant water, filled with green scum in summer, are 

 approximately 1,500 feet above the sea; Methy Lake, 1,700 feet; the crest 

 of Methy portage, 1,760 feet, abundantly strewn with bowlders, probably 

 belonging to a belt of morainic drift; and Clearwater River, a tributary of 

 the Athabasca, at the north end of this portage, 1,100 feet. A very steep 

 descent is made to the Clearwater, which flows westward in a great valley, 

 formed by preglacial erosion, 2 to 3 miles wide.^ 



'Narrative of a journey to the shores of the Polar Sea, in the years 1819, 1820, 1821, and 1822, by 

 John Franklin, R. N., F. R. S. ; including an Appendix of Geognostioal Observations by John Rich- 

 ardson, M. D., surgeon to the expedition. 



Also, see Sir John Richardson's Arctic Expedition in Search of Sir John Franklin ; and descrip- 

 tions of Methy portage and its vicinity, by Prof. John Macoun (Geol. Survey of Canada, Report of 

 Progress for 1875-76, pp. 94, 174) and by Dr. Robert Bell (Bulletin, G. S. A., Vol. I, p. 290). 



The elevations stated are increased 200 feet above the estimates given by Richardson, which 

 addition (or perhaps 100 feet more) is required by comparison with reliable determinations of eleva- 

 tions on the Saskatchewan and Peace rivers. 



