The Grand Prismatic Spring of Yellowstone National Park is the largest thermal spring in the US and the thirds largest in the world. But the sheer size of this 61-100 meter (200-330 feet) wide ...

The color given off by Grand Prismatic's bacteria is a pigment that acts as a sunscreen. By the time the water gets to the edge of the spring, it has cooled to about 147 degrees.

How the Grand Prismatic Spring Gets Its Kaleidoscopic Colors The beating heart of Yellowstone National Park is without a doubt the Grand Prismatic Spring—the largest hot spring in the U.S.

The incident occurred at Grand Prismatic Spring near Old Faithful as tourists were enjoying a close-up view of the famous and popular hot spring.

The bison died in the boiling waters of the Grand Prismatic Spring. This happens from time to time, but usually not in front of a crowd.