The Morning Glory hot spring!

Tourists view the Morning Glory hot spring in the Upper Geyser Basin of Yellowstone National Park. The original name of the Morning Glory Pool was Convolutus. It was given that title in 1883 by the wife of an assistant park superintendent, after the Latin word for the morning glory flower, which the pool’s blue color resembles. Recently, however, the pool has started to go by another name “Fading Glory.”

It was named after the flower that its color resembled. If you had visited Yellowstone in the 1940s, the pool would have looked something like this:

But then, the water’s color changed. The pool took on a distinctive hue, a Wicked Witch of the West-style green with orange and yellow edges. If you visit today, it looks something like this:

What caused the change? There was always a prime suspect: humans. Visitors to Yellowstone have been known to throw pennies, rocks and all sorts of garbage into Morning Glory. But their culpability wasn’t proven until recently, when a group of researchers created a mathematical model, based on optical measurements, that intended to explain just what happened.

Nowhere is the damage from people more apparent than in the once beautiful Morning Glory Pool, now referred to as “Fading Glory” or “Garbage Can,” because early visitors and vandals threw trash, coins, and even, reportedly, a couch into the baby blue water. Some also removed the delicate scalloped border for souvenirs.