1 6 ALASKA GLACIERS 



reached the three-eighth-mile limit is roughly measured 

 by the age of a half-grown forest. 



GLACIER BAY 



The next depression west of Lynn Canal is broader, 

 as well as more complex in the details of its config- 

 uration, and its general trend is northwestward in- 

 stead of northward. On the west it is separated from 

 the Gulf of Alaska by the Fairweather Range, the 

 dominant mountain mass of this region. Glacier Bay, 

 occupying its main axis, sends many branches into 

 the troughs among its hills and mountains, and would 

 be still more complicated in outline but for the clog- 

 ging of the valleys by glaciers. Six of its inlets head 

 against ice walls, from which bergs are constantly 

 falling. 



The glaciers of this basin are better known to the phys- 

 ical geographer than any others of the Alaska belt, and 

 one of their number, the Muir, enjoys the same preemi- 

 nence in popular acquaintance and appreciation. The 

 group was explored, sketched, and studied by Muir in 

 1879 and 1880. Wright made a visit in 1886, producing 

 a rough map and working out the main elements of the 

 later glacial history. Reid, in 1890 and 1892, executed 

 a careful survey of the shores, the lower portions of the 

 tidal glaciers, and a broad inland tract including the 

 greater part of Muir Glacier; developed much further 

 the history of recent changes; and instituted a number 

 of investigations bearing on the physics of glaciers. 

 Minor studies were made by Gushing (1890) and Rus- 

 sell (1890), the map work has been extended by the 

 Canadian Boundary Commission, and a fine series of 

 photographs were made by the Commission in the sum- 

 mer of 1894. 



