Last updated: 02:20 PM ET, Tue March 17 2015

Tourists, Please Don't Throw Anything Into Yellowstone’s Morning Glory Pool

Destination & Tourism | Donald Wood | March 17, 2015

Tourists, Please Don't Throw Anything Into Yellowstone’s Morning Glory Pool

Photo courtesy of Wikipedia

Green may be a celebratory St. Patrick’s Day color, but the unwanted appearance of green and yellow colors in Yellowstone National Park’s normally electric blue Morning Glory thermal pool are reportedly a result of coins and other items visitors throw into the water each year.

According to, researcher Adam Hoffman talked about how the new microbes in the water from the debris are the reason behind the change. Hoffman explained further how the debris at the bottom of the thermal pool is the root of the issue:

“Over the years...tourists have tossed lucky coins, rocks, and other debris into the pool, partially blocking the underground heat source and lowering the temperature of the spring to a range habitable by photosynthetic microorganisms that probably didn’t live there before.”

Courtesy of and Robert Robi on Twitter, the images of the thermal pool are stunning:

The Morning Glory thermal pool is one of the most visited attractions Yellowstone National Park, and the nearly three million people who visit each year are partially responsible for the color distortion.

Montana State University Ph.D. student, Paul Nugent, told FoxNews that removing the debris at the bottom of the thermal pool may not be enough to change the color back. He is leading a research team that will be able to determine how natural and human elements impact the water.

While it is true that the thermal pool has lost the blue color that helped give it the name Morning Glory—a colorful flower that is often bright blue—the green and yellow colors emanating from the hole now are beautiful in a different way.

If there is concern about doing too much damage to the thermal pool, officials at Yellowstone National Park may need to consider rules changes in order to keep the attraction from deteriorating any further.


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