104 ALASKA GLACIERS 
miles. The retreat was interrupted by a temporary ad¬ 
vance between 1890 and 1892. 
La Perouse Glacier is practically at maximum now. It 
has not been greater for centuries, except that it was a 
little longer a few years ago, when it invaded a mature 
forest. As its neighbors at the east and west were much 
smaller a centur}^ ago, analogy suggests that the present 
maximum was preceded by an important minimum. 
In Disenchantment Bay and its dependencies a great 
retreat, amounting to at least five miles along one channel 
of outlet and thirty miles along another, has been in prog¬ 
ress for more than a hundred years. There is evidence 
of other changes, but their order and dates are unknown. 
Columbia Glacier is practically at maximum now, and 
was nearly as large in 1794, but an important minimum 
probably occurred within the nineteenth century. It has 
not been greater than now for centuries, except that it was 
a little larger about the year 1892, when it invaded a 
mature forest. 
The numerous glaciers of Port Wells, including College 
and Harriman fiords, may have a harmonious recent his¬ 
tory, but the data are too meager to warrant a definite state¬ 
ment. They are somewhat smaller than at a maximum 
which may have occurred fifty to one hundred years ago. 
Grewingk Glacier has not for centuries been much 
larger than now. It was somewhat larger between fifty 
and one hundred years ago, and may have had a subse¬ 
quent maximum of nearly the same extent. 
The most conspicuous fact brought out by the compari¬ 
son of local histories is that they are dissimilar. Never¬ 
theless, there are limited resemblances. The Glacier Bay 
and Disenchantment Bay histories agree in including a 
great retreat, occupying more than a century. The Port 
Wells and Grewingk histories agree in a moderate retreat 
occupying something less than a century. The La Perouse 
