Smithsonian Report. 1950.- Black 



1. Bridge piling on tlie Ala.ska Railruaci broken by downhill creep in mud on 

 top of perniafro.'it in the Nenana River Gorge, central Ala.'^ka. Photo- 

 graphed September 24, 1948. 



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2. Slump ill gravel on s^treet in Barrow, where ^team line produced thawing of 

 permafrost. Photographed May 12, 1950. 



