Yellowstone's thermal pools are iconic for their naturally unnatural bright colors, but one, the Morning Glory Pool, actually used to be an entirely different hue. So what chamnged? Tourists descended on the busy national park and, through the decades, have tossed so much rubbish into the thermal pool that the pool's color has completely changed.
The Morning Glory Pool was originally named for its remarkable resemblance to the blue flower of the same name that blooms at early dawn. And for decades, the attraction beamed brightly from below with a vibrant light blue.
Photos of the Yellowstone hot pool prior to the 1950s show an unmistakably blue pool. Now, thermal features naturally undergo changes, but we have reason to believe that this color change to Morning Glory Pool was not entirely natural.
TikTok user @geodesauras shared some facts about the Morning Glory Pool. People visiting have thrown so much rubbish into the pool's water—such as coins, trash, rocks, and logs—that it clogged the natural vents under the surface.
The debris became embedded in the sides and vent of the spring, affecting water circulation and accelerating the loss of thermal energy, according to the National Park Service. The water could not circulate properly due to this blockade of garbage; and through the years, it has caused the water temperature to drop. So Morning Glory's appearance changed as its temperature dropped. Bacteria that wouldn't have been able to thrive in the pool's previously hotter temperatures started to live on the periphery. The microbes are called photosynthetic microorganisms. Over time, that rim bacteria—which shows up as an orange and yellow color—has crept in toward the center, pushing out any of the blueish tones for which the pool was known.
Now, instead of the brilliant blue, the Morning Glory Pool displays an array of green, yellow, and orange, like many other pools in Yellowstone. On the surface, it might seem as if restoring the pool's natural color would be as simple as removing the trash. This has been attempted at least once. Rangers concerned about the human impacts to Morning Glory's color in the 1970s partially drained the hot spring and attempted to remove as much trash as possible, but without success.
Enjoy the outdoors?
Sign up for daily stories delivered straight to your inbox.