Copper River Delta picture By Dennis Zaki
Geologists had found that the glaciers had fused during the past several centuries, and the leader of a U.S. Army expedition up the Copper River in 1885 reported that the nose of Miles Glacier was then about 120 yards from the site of the bridge. By 1908, both glaciers had receded to provide a gap of about three miles.
Starting in April 1909, workers scrambled to complete the Million Dollar Bridge, spurred on by a U.S. law that gave railroad developers four years to complete a designated route. After four years, the government would tax them $100 per operating mile per year. Contractors finished the bridge by midsummer of 1910.
Soon after construction of the Million Dollar Bridge (which cost $1.4 million to build), the glaciers continued to threaten the railroad.
In August 1910, two glaciologists from the National Geographic Society studied the sudden advances of both Miles and Childs glaciers. A northern lobe of Childs Glacier began creeping toward the bridge in June, and by August it was moving eight feet per day. On August 17th, the 200-foot face of the glacier was 1,624 feet away from the bridge.
Ralph Tarr, one of the glaciologists, speculated on what would happen if the glacier continued to advance in 1911.
“It is absolutely certain that no corps of engineers could save the bridge and railway if the glacier should advance that far,” he wrote.
Childs Glacier did not engulf the bridge, but the glacier crept to within 1,475 feet in June 1911. Childs and Miles glaciers have since retreated, sparing the Million Dollar Bridge, which served the railway from 1910 until 1938, when low copper prices forced the shutdown of the Copper River and Northwestern Railway. The bridge survived nature’s whims until March 27, 1964, when the Good Friday Earthquake knocked the northernmost span from its concrete piling.
First published October 3, 2007
Since the late 1970s, the director of the Geophysical Institute at the University of Alaska Fairbanks has supported the writing and free distribution of this column to news media outlets. This is Ned Rozell’s 20th year as a science writer for the Geophysical Institute.