7 6 



ALASKA GLACIERS 



was probably originally shoal. They may have been 

 formed recently, or at some earlier epoch. 



The drainage of the ice included several streams 

 flowing eastward to the chain of lakes, and we noted 

 two important streams from the western ice cliff. One 

 of them issued from a cave at the water's edge near 

 the western limit of the cliff, the other from a sub- 

 merged and invisible tunnel near the middle of the 

 cliff. The last mentioned was probably the largest of 

 all the draining streams. It rose to the surface at the 

 base of the ice cliff and flowed southward over the 



salt water, forming a 

 broad lane of milky fresh 

 water with a visible cur- 

 rent and at times nearly 

 free from floating ice. 

 At most points the 

 forest of spruce and hem- 

 lock approached close 

 to the ice, its relation 

 being similar to that ob- 

 served at La Perouse 

 Glacier. At the western 

 margin of the main ice 

 cliff, where the glacier 

 crowded against a steep 

 rock slope, there was a belt of bare rock, from 200 

 to 300 feet broad, between the ice and the forest 

 (fig. 38). This belt was strewn with fragments, not 

 only of rock but also of wood, and trees were freshly 

 overthrown at the margin of the forest. At the time 

 of its attack on the forest the ice must have been 100 

 feet deeper than in the summer of 1899, and it also 

 extended farther southward, as shown by a push-mo- 

 raine of rock at the water margin, 800 feet from the 



FIG. 38. WESTERN EDGE OF 

 COLUMBIA GLACIER. 



Shows barren zone and forest. From a 

 photograph taken in June, 1899. 



