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in 1894, and Otto Klotz has written about the glaciers, 

 particularly about the great recession. The Harriman 

 expedition visited the bay in 1899, and G. K. Gilbert [31] 

 has discussed the phenomena observed ; while Henry Gan- 

 nett and John Muir have presented briefer accounts. 

 C. L. Andrews [1] visited and described Muir glacier in 

 1903. F. E. and C. W. Wright [95] studied and mapped 

 the glaciers in 1906, but have not as yet published their 

 full report. In 1907 the Boundary Survey made a new 

 map of the Glacier Bay region. Fremont Morse [60] and 

 Otto Klotz [38] have described the condition of the glacier 

 in that year. Tarr and Martin [77] made a brief study 

 of Muir glacier in 191 1. Thus we have a fairly full 

 record of the conditions at Muir glacier from 1879 to 191 1. 



Glacier History similar to that of Yakutat Bay. 



The history of Muir glacier and the other ice tongues 

 of Glacier bay is strikingly similar to the glacial history 

 of Yakutat bay. There was (a) an ancient period of 

 expansion of the glaciers, followed by (b) a great recession 

 during which Muir glacier was even smaller than at present. 

 Then came (c) a second period of expansion, followed by 

 (d) the modern recession, which is still in progress. This 

 modern recession has not yet been interrupted by such 

 a great series of forward movements as the recent advances 

 of nine glaciers in Yakutat bay, though (1) Muir glacier 

 advanced slightly between 1890 and 1892, (2) Rendu 

 glacier pushed forward about if miles (2-4 km.) between 

 1907 and 191 1, and (3) an unnamed, adjacent, cascading 

 glacier advanced over 1,300 feet (395 m.). 



The evidence of the ancient expansion is found in 

 the glaciated topography and the glacial deposits of the 

 fiord. The proof of the ensuing recession comes from the 

 buried forests. There are trunks of mature trees in 

 deposits which rest upon glaciated surfaces, some logs 

 found by Tarr and Martin being as far north as the ice 

 front of 191 1. The second expansion is indicated by the 

 youthful vegetation of southern Glacier bay and by the 

 historical observations of Whidbey and Vancouver in 1794. 



