CACHE COUNTY, Utah (ABC4) — Summer will officially be here this week and many Utah mountain peaks are still holding onto some snow. If you’re lucky enough to get out there before it’s all gone, you may see a natural phenomenon called watermelon snow. 

In Cache County, watermelon snow has turned the mountains into different shades of pink, red, and orange. What causes watermelon snow? Naturally occurring algae. 

“I thought that was pretty cool,” Wallace Salle told ABC4. The young boy, and his family, were visiting Tony Grove Lake all the way from Minnesota. They were amused and confused by the bright pink splotches of snow that surrounded the lake. Salle added: “At first, I was like, ‘Is someone painting it or something?’”  

Whether visiting from Minnesota or from Cache Valley, the watermelon snow was eye-catching and unexpected to all those who visited the area.  

“I think it’s really pretty,” local resident Dru Davis stated. “I love the color. Pink is my favorite color. I think it looks almost like it’s spray painted.” Davis, like Salle, was on the mountain with family.  

“It was pink normally,” Salle said referring to the watermelon snow. “And then I stepped in it and then my shoe became orange, and then I walked in the snow again and it was orange.” Salle, like a handful of other hikers who spoke to ABC4 Reporter Kade Garner, had the bottom of his shoes turn a bright orange after walking on the snow.

While undisturbed portions of snow were hues of pink and red, passersby could easily spot where someone had walked through the snow as their footprints were a striking peach color.  

So, what causes this strange snow? “It’s actually a green algal bloom that’s occurring on the snow’s surface,” Scott Hotaling explained. Hotaling is an assistant professor at Utah State University’s Department of watershed sciences. He’s been studying watermelon snow, and the algae that cause it, for a few years.  

“The snow algae produce a pigment that basically darkens their cells, and it acts as both a protection against UV, so it protects their DNA and other aspects of their organelles from damage because they’re in such a bright place,” Hotaling stated. “But then also, it has a secondary benefit of causing their cells to absorb heat which melts the snow around them which allows them to actually access water because, you know, we’re out here in a world of water right now but none of it is accessible.”  

Basically, the algae turn red to protect itself. Think of it like how skin tans to protect itself from sun damage. As the algae darken in color, it retains more heat from the sun. In turn, it causes the snow to melt faster.

Hotaling said in years of drought this could be a problem. He is currently working to figure out how much of Utah’s snowpack melts as a result of algae and what can be done to prevent it from becoming a problem. The research is in its infancy but could see results within two years.    

After a winter with record-breaking snow, some people won’t mind if it helps speed up the melting process a least a little. “I love the snow,” Davis said. “I’m kind of tired of it. I love summer. I miss swimming in lakes but besides that, I think it’s awesome.”