Images

Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.

Map showing locations of placer mines in the Alaska Resource Data File (ARDF, red crosses), primary mineral districts that contain targeted critical minerals (black boxes) and locations that were sampled by the USGS in 2022 through 2024 (yellow stars).

USGS scientists measure flooding on the Mendenhall River as water releases from Suicide Basin’s glacier-dammed lake on August 13, 2025. 

The sun sets over Katmai National Park and Preserve. Katmai is one of four monitoring sites for the Nearshore Component of the Gulf Watch Alaska program.

Ridged hull inflatable skiffs are used by scientists to conduct rocky intertidal monitoring for the Nearshore Component of the Gulf Watch Alaska program. Data are collected to estimate percent cover and densities of intertidal invertebrates and algae to assess change in communities from sheltered rocky shorelines.

A scientist holds a HOBO temperature logger that was recently retrieved from a sampling site at Katmai National Park and Preserve. The sensor end of the HOBO was partially covered by a small sea star (Leptasterias spp.) when recovered from the site. The temperature loggers record the water temperature.

A pair of scientists observe sea otter foraging behavior at Katmai National Park and Preserve. Questar telescopes are used to assist with prey identification.

A male Northern Sea Otter sleeps on his back after foraging for clams at Katmai National Park and Preserve.

A native bubble bee pollinates a wild celery. There are 22 species of bumblebees in Alaska and all are essential pollinators during the short growing season.

A Black Oystercatcher watches over a few days-old chick at Katmai National Park and Preserve. These shorebirds are monitored on a yearly basis as part of the Gulf Watch Alaska (GWA) long-term monitoring program.

A scientist examines the teeth from a sea otter skull found on a beach at Katmai Nation Park and Preserve. Teeth are collected in the field and each sea otter is aged using cementum annuli counts. Cementum annuli are the rings of collagen fibers in tooth roots.

Rivers across northern Alaska have recently turned orange in color. Because of their appearance, they are often called “rusting rivers.”

In this photo, Paul Hershberger is conducting research in the Seattle Western Fisheries Research Center wet laboratory. He is working to study diseases in fish.

USGS staff inspecting monitoring equipment in Suicide Basin. Suicide Basin is a side basin of the Mendenhall Glacier above Juneau, Alaska.

A small group of Pacific walruses consider entering the water as they assess their surroundings.  A calf can be seen in the back of the group.  USGS and the U.S.

Emily Baker (USGS) sampling a snow-pit on Kahiltna Glacier at 3,055 m (10,023 feet).

A core section from Kahiltna Glacier at 3,055 m (10,023 feet) on September 30, 2024, showing ice layers in finegrained snow. These "internal accumulation" layers form when water from surface melt percolates into the snowpack and refreezes.

These are large glaciers, and even with a helicopter they make you feel very small. Here the scale of the crevasses is illustrated by the small helicopter shadow. This is typical of the complicated topography and significant relief that is common on larger glaciers in Alaska.

Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.

Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.

Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.