Even though Old Faithful may be the most talked-about feature in Yellowstone, Grand Prismatic Spring is the largest hot spring in the country, and the most beautiful wonder in the park. See what makes this remarkable spring glow with color by reading more about it below.

Among all of Yellowstone National Park’s 2.2 million acres, one enormous hot spring truly stands out. Grand Prismatic Spring is the largest hot spring in America, and it’s one of the most incredible natural wonders in Wyoming.

Flickr / Sam Beebe

Not only is Grand Prismatic the largest hot spring in the United States, it’s also the third largest in the world! Only Frying Pan Lake (New Zealand) and Boiling Lake (Dominica) are bigger.

Flickr / Bernd Thaller

Head to the Midway Geyser Basin to see it up close - but not too close! Grand Prismatic is 370 feet wide, and the pool itself is 160 feet deep. More than 560 gallons of water are discharged each minute, and the temperature sits at 160 °F.

Flickr / Eric Kilby

It didn’t take long for the Hayden Geological Survey, exploring the park in 1871, to note this incredible thermal feature. The surveyors were mesmerized by the colors - blue, green, yellow, orange and red can all be seen in the spring and surrounding area.

Flickr / Clint Losee

The deeply saturated and vivid colors of the spring and its surroundings vary, depending on the season. If you visit in summer, you’ll see lots of orange and red surrounding the bright blue water. In the winter, the ground is more of a dark green.

K. Magaraci

All of these colors are the result of microbial mats around the edges of the mineral-rich water. The color, and how much of i shows through, depends on the ratio of chlorophyll to carotenoids in the runoff, and the temperature gradient.

K. Magaraci

Grand Prismatic Hot Spring is the most photographed thermal feature in Yellowstone - more people snap pictures here than at Old Faithful! Can you blame them? The colors are absolutely astounding.

Flickr / Jake Pfaffthenroth

Share your best pictures of Grand Prismatic on our Wyoming Nature Lovers group, and connect with more people who absolutely love Yellowstone!

Flickr / Sam Beebe

Flickr / Bernd Thaller

Flickr / Eric Kilby

Flickr / Clint Losee

K. Magaraci

Flickr / Jake Pfaffthenroth

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Address: Grand Prismatic Spring, Wyoming 82190, USA