In the remote wilderness of the Brooks Mountain Range in Alaska, where untamed rivers wind through vast expanses of tundra and towering mountains, a peculiar and alarming phenomenon is taking place. Since 2017 at least 75 pristine waterways, which once shimmered with crystalline clarity, have taken on a haunting hue of orange and now contain very concerning toxic metals and minerals.

As speculation gives way to investigation, a team of researchers has been looking at the region's rapidly thawing permafrost—a phenomenon they suspect may hold the key to unraveling this disturbing transformation. 
 
This week the Traveler’s Lynn Riddick talks with key scientists with the National Park Service and the University of California Davis on their new study that investigates these altered headwater tributaries, including ones in five national parks and a number of other protected areas. Among their findings are impacts to aquatic life, ecosystems, drinking water and the locals who rely on fishing for subsistence.

Companion Article: Why Melting Permafrost Is Turning Alaskan Streams Orange