What’s the ‘rainbow pool’ spotted in SC national park? It’s not oil, experts say

This “rainbow pool” seen in Congaree National Park, South Carolina looks like the result of an oil spill, but according to park officials, it’s a totally natural occurrence.

Conditions must be perfect, but if a lucky hiker visits Congaree at the right time of year, with the weather just so, and looks at the right spot at just the right angle, they’ll be rewarded with a vibrant display -- not of pollution, but of natural decay.

“Many times they are the result of decaying vegetation, especially cypress cones and needles, that release their natural oils,” the U.S. Department of the Interior posted Monday on Facebook.

A second cause, “bacteria breaking down iron in the soil,” can also be at play.

“Very still waters are a must,” according to Congaree park officials, as quick movement can break the surface sheen apart.

Early morning or evening, as the sun either rises or sets, are the best times to go looking. Also, the effect is more pronounced the less it rains

Congaree National Park posted the picture last week, and hundreds have flocked to it, commenting “beautiful,” wishing they could go, or making plans to visit in the future.

“Future date destination,” one commenter said.

“Can we plan a trip here when I visit?” someone commented, tagging another. “I mapped it and it’s about an hour and a half drive.”

Congaree, like many parks across the country, has modified its operations under coronavirus. While much of the park is closed or otherwise off limits, the backcountry hiking trails remain open, according to the park.

This story was originally published March 30, 2020 at 8:50 PM.