National Geographic : 1951 Jun
843 Don C. Knudsen from Frederic Lewis Grinding, Bobbing Ice Rafts Speed Past the Glacier's Grooved Face Gore and Brink, at the bottom of the gorge, examine ice laid down perhaps thousands of years ago. Geologists consider glacial ice, formed by re-crystallization of snow, akin to metamorphic rock, such as marble, the outgrowth of limestone. Undeformed ice, if subjected to pressure in a laboratory, develops a similar structure. Floods from Lake George's 1915 breakup surprised some 1,500 men camping near Knik River. Building the Alaska Railroad's 470-mile line from Seward to Fairbanks, they were using equipment left over from the Panama Canal job. Engineers and surveyors had to swim and wade the icy waters. Loose gold is worked in near-by Metal Creek, but production is small.