SFGATE - When John McPhee and his ragtag crew first kayaked into the pristine Alaskan wilderness in 1975, they were awestruck.
The author, who chronicled his reconnaissance trip in the literary classic “Coming into the Country,” was surrounded by an abundance of untouched flora and fauna. Beneath them, Arctic grayling, chum salmon and Dolly Varden swam in “the clearest, purest water” they had ever seen.
But if McPhee returned to the Salmon River in 2025 — exactly half a century after his initial exploration — chances are he would be deeply disturbed by what he saw.
According to a Sept. 8 paper published in the proceedings of the National Academy of Sciences, an iconic Arctic watershed in Alaska’s Brooks Range has recently turned a dark, murky orange color, alarming scientists throughout California and Alaska.
“This is what acid mine drainage looks like,” Tim Lyons, a biogeochemist at UC Riverside, told the university in a September 2025 article. “But here, there’s no mine. The permafrost is thawing and changing the chemistry of the landscape.” According to the research paper, authors believe that permafrost — soil, rock or sediment that’s been frozen for at least two years — is thawing, exposing sulfide minerals and delivering iron and other potentially toxic metals to the remote Alaskan wilderness.