Cauldron Bubble

Cauldron Bubble by Robby Edwards

Yellowstone National Park, July 2006

Double, double toil and trouble;
Fire burn, and cauldron bubble.
~William Shakespeare — MACBETH; Act IV, scene 1

Crested Pool churns at a slow boil while the clouds in the sky at sunset are reflected in the water surrounding it.

The depth of Crested Pool is 42 feet and water in it maintains a constant boil, but may shift between just simmering or a violent boil, when the water may as high as 8 to 10 feet.