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 Midway Geyser Basin's Grand Prismatic Spring is the largest hot spring in Yellowstone and one of the largest hot springs in the world. Measuring approximately 370 feet in size and around 121 ...

Grand Prismatic Spring in Yellowstone National Park is the largest hot spring in North America and the third-largest in the world, after Frying Pan Lake in New Zealand and Boiling Lake in Dominica.