USGS Reports on Colorful Snow: Pink, Blue Green, and Orange-Brown Snow Dot Beartooth Mountains in Wyoming

Images of snow algae and snow cyanobacteria on snow fields in the Beartooth Mountains near the Beartooth Pass Summit. This image shows pink snow algae on the upper snowbank and blue-green and orange-brown snow cyanobacteria in the lower portions of the snow patch. Image: Jeff Having, University of Minnesota — Images of snow algae and snow cyanobacteria on snow fields in the Beartooth Mountains near the Beartooth Pass Summit. This image shows pink snow algae on the upper snowbank and blue-green and orange-brown snow cyanobacteria in the lower portions of the snow patch. Image: Jeff Havig, University of Minnesota

While there’s an addage “don’t eat yellow snow”, did you know that snow in a rainbow of colors exists in the natural environment? In a report released today by the Yellowstone Volcano Observatory (YVO) of USGS, Dr. Jeff Havig and Professor Trinity Hamilton, researchers in Plant and Microbial Biology and Earth and Environmental Sciences at the University of Minnesota, the existence and science behind colorful snow is shared.

Microorganisms that live on perennial snow fields help alter their color. Colorful patches of pink to crimson can form on snowpack; these colors are due to pigments produced by snow algae. Algae are single-celled organisms that often live in lakes and oceans, but can also be found thriving in near-freezing temperatures on top of snow.

A pink snow algae bloom is scraped off the snow surface with a rock hammer in the Beartooth Mountains of Wyoming. Image: Jeff Havig, University of Minnesota

In addition to pink snow algae, there are also species of cyanobacteria that have adapted to the cold conditions. Cyanobacteria is photosynthetic bacteria that changes color as a result of colorful photosynthetic pigments contained within it; these pigments can produce colors like orange, green, brown, and grey.

According to the study released today, “When temperatures are consistently below freezing, the algae and cyanobacteria go into hibernation to wait until warmer temperatures return. Thus, when visiting snowfields or glaciers during the winter, one will not see patches of pigmented colors, but late spring through to early fall are ideal times to watch for “blooms” on glacier and snow field surfaces.”

One place to see colorful snow now is in the Beartooth Mountains located northeast of the Northeast Entrance of Yellowstone National Park, near Silver Gate, Montana. The mountains here host perennial snow fields that often contain these colorful displays of snow at this time of year.

The full report and more pictures can be seen at YVO’s website here: https://www.usgs.gov/observatories/yvo/news/pink-snow-algae-blooms-high-mountains-yellowstone-and-around-world