GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. 73 



feet), the sides of which triangle are approximately 3x4x5 miles (plate xxvin, 

 figure 2). The area is located upon the western slope of the Great Divide, the 

 crest of which extends in a curve from Mt. Baker to Mt. Gordon. The collecting 

 area is estimated at about 6 2 square miles. Upon the western slope of the Divide 

 it presumably receives more precipitation than falls in the Lake Louise Valley 

 and that of the Ten Peaks. From the meager data available at Field we calcu- 

 lated that the precipitation may amount there to 42 inches per annum, page 1 1 . 

 To the north it would be somewhat less and may be assumed to be 40 inches. 

 Over the neVe" area the great bulk of this would fall as snow, but that which was 

 precipitated as rain would be absorbed at once and rendered available for the 

 glacier, representing about 33 1 feet of snowfall each year. This amount over the 

 collecting area, the region in which the snow is manufactured into glacial ice, would 

 represent some 224 million cubic yards of snow, or about 24,396,000 cubic yards 

 of ice, available each year for the Yoho. If our assumed data are approximately 

 correct, this must represent the amount of ice to be disposed of annually by 

 melting and evaporation. Converted into water, this volume of ice would pro- 

 duce 22,372,000 cubic yards of water, or 604,032,000 cubic feet of the same. 

 Distributed over the months May to September inclusive, during which time 

 the melting is most active, this would give an average flow of about 46 cubic 

 feet per second. During midsummer the flow is probably four or five times this 

 amount, due largely to the fact that the actual area drained is much larger than 

 the single n6v6 field, and that the melting is now at a maximum. The ne"ve" 

 coming in from the eastern, or Mt. Gordon side, as well as that from the western 

 or Mt. Collie side, has already been compacted into glacial ice before reaching 

 the main flow from Mt. Baker. This ice is incorporated into the Yoho ne"ve" 

 with whatever debris it may be carrying. The absence of overhanging cliffs 

 about the ne"ve" area, quite in contrast with the Victoria and Wenkchemna 

 glaciers, prevents the neVe" snow from becoming charged with rock de"bris. 

 The glaciers from the slopes of Gordon and Collie, as well as the main stream 

 from Mt. Baker, are carrying only subglacial material, of which we have 

 evidence later. To this is to be ascribed the freedom of the glacier from surface 

 debris. This condition of the ice, combined with its southern exposure to the 

 sun, is unfavorable to the maintenance of a glacier at low altitudes. This is 

 entirely obviated, however, by the greater bulk of ice available when this 

 glacier is compared with the two previously described. 



3. DISTRIBUTARY. 



Except for the ne"ve"-covered glaciers above noted from Mts. Gordon and 

 Collie, the Yoho has no tributaries; but instead, what has been termed a dis- 

 tributary, to assist it in getting rid of its ice supply. A considerable volume of 

 ice is deflected around to the eastern side of the rock embossment and is there pre- 

 maturely melted. (See plates xxvi, xxvin, figure 2, and plate xxvii, figure 3.) 

 This tongue of ice forms a very pretty little glacier, one-half mile long by one- 

 quarter mile broad and tapering down to a blunt nose (plate xxvii, figure i). 



