April 16, 2021 — New research indicates that the Alsek River will change course dramatically over the next few decades. Geologists with the National Park Service predict that glacial retreat related to climate change may move the mouth of the river 20 miles away from its current location. This could pose challenges for raft trips and fishing in Glacier Bay National Park.
The Alsek River originates in the Yukon Territory and flows hundreds of miles south before emptying into the Pacific Ocean at Glacier Bay National Park. Near the end of its journey, the river widens into Alsek Lake. It’s currently separated from the Grand Plateau Lake by a glacier.
But when that glacier melts enough, the lakes will combine and eventually drain into the ocean down a steep embankment.
Michael Loso is a Park Service geologist who researches the Alsek changing course.
“Presently, the Alsek River can’t get there because this glacier, you know, this big pile of ice is in the way,” Loso said. “But really, the thrust of our paper is to make the case that once that glacier ice completely goes away, by a combination of melting and calving into the two lakes, you would be able to paddle your raft right on over to Grand Plateau Lake because the two lakes would be combined.”