144 



between 1905 and 1906. Almost coalescing with the 

 Variegated, is Orange glacier, entirely confined in its moun- 

 tain valley, unchanged since first observed in 1905, and 

 forming the western end of a through glacier, whose other 

 end is just back from the shore of Nunatak fiord. Near 

 the southeastern end of this through glacier, Butler glacier 

 descends from the mountains, and, emerging from its 

 mountain valley, spreads out, as Variegated glacier does, 

 into a moraine-covered piedmont bulb occupying a broad 

 valley mouth almost on the shores of Nunatak fiord. 



Just east of this piedmont ice bulb is the ice cliff on 

 the tidal Nunatak glacier, whose history from 1891 to 

 1909 was that of continuous recession for over 2\ miles 

 (4 km.), followed by an advance of 700 to 1,000 feet (200 

 to 300 m.) between 1909 and 1910. It has also a wasting 

 land tongue or distributary, and above its end hangs the 

 ice fall of Cascading glacier, the type of a series of similar 

 glaciers in this region and elsewhere in Alaska. On the 

 north side of the fiord is Hanging glacier, which no longer 

 cascades over the lip of its hanging valley. Hidden 

 glacier, to the southwest of Nunatak glacier, was of pe- 

 culiar interest in 1899 and 1905 because of the valley train 

 which separated its stagnant terminus from the sea. These 

 outwash gravels rested for a distance on the glacier ice, 

 which, by melting, gave rise to a pitted plain. All this 

 is now destroyed, for in 1909 Hidden glacier was utterly 

 transformed, having undergone a spasmodic advance of 

 over 10,000 feet (3,000 m.) since last seen in 1906. 



Ancient Expansion of Yakutat Bay Glaciers. 



Throughout the entire Yakutat Bay region the evi- 

 dence is complete that all the glaciers have been far more 

 extended at a former period than at present [72, 73]. The 

 period of greatest extension of the glaciers was recent, in 

 a geological sense, but was several centuries ago, for a 

 mature forest grows on the deposits laid down by these 

 expanded glaciers. 



There are several lines of evidence for concluding 

 that these glaciers were formerly far greater than now. 

 In the first place, the valleys throughout the region show 

 clear signs of pronounced glacial erosion. The valley 

 walls are scored, grooved, polished and smoothed to ele- 

 vations far above sea level, and, in those valleys where 



