Morning Glory Pool, Hot spring in Upper Geyser Basin, US

Morning Glory Pool is a hot spring in the Upper Geyser Basin of Yellowstone National Park. Its oval basin has a rim of yellow and ochre mineral crust; the water is pale blue at the shallow edges and deep blue in the center, with white steam rising above. A wooden walkway runs along the far edge.

In 1883 Mrs. E. N. McGowan, wife of Assistant Park Superintendent Charles McGowan, named the spring "Convolutus", the Latin name of the morning glory flower it resembles. By 1889 the name Morning Glory Pool was in common use in the park, and the feature has also been called Morning Glory Spring.

The name comes from Mrs. E. N. McGowan, wife of assistant park superintendent Charles McGowan, who in 1883 called the spring "Convolutus", the Latin name of the morning glory flower it resembles. By 1889 the English name was in common use. A park sign near the pool discusses damage from objects thrown in and asks whether Morning Glory is becoming a "Faded Glory".

Visitors must stay on marked boardwalks since the water is extremely hot and the paths also protect the fragile ecosystem. Stepping off designated routes damages the natural color patterns and poses safety risks.

Over decades, visitors threw objects into the pool that slowed water circulation and altered its original deep blue color. This unintended transformation reveals how human actions can subtly reshape natural systems.