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Yellowstone National Park, Wyoming

Grand Prismatic Spring

The largest hot spring in the US is, as the name suggests, a stunning show of natural color 

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With a name like the Grand Prismatic Spring, a natural wonder has a lot to live up to and this huge hot spring in Yellowstone Park is more than up to the task with its vivid rainbow ring of colors.

First discovered in the early 1800's amidst the geysers and sulfurous bubblings of Yellowstone National Park, the record setting natural wonder has been stunning visitors for over a century. The pool is a piercing blue surrounded by rings of color ranging from red to green. The otherworldly effect is caused by varieties of pigmented bacteria and microbes that thrive in the warm, mineral abundant waters surrounding the hot spring. Changing along with the seasons the colors fade and grow more deep depending on what type of bacteria is thriving in the weather at the time. The center of the pool, where the water boils up from underground is so hot that the water is actually sterile. This produces a shockingly clear and bold blue color that the spring maintains year-round. 

The Grand Prismatic Spring is one of America's more beautiful sites to look at, just don't touch as the boiling heat could likely melt skin from bone, mixing blood red into the deep blue.  

Know Before You Go

From Madison Junction head south towards Old Faithful. Or travel north from Old Faithful. Park in the Midway Geyser parking area, and it is a short walk uphill on the boardwalks. Parking is limited, and the boardwalks become crowded if 3 or more tour buses arrive at the same time. There is a picnic area 1/4 mile north which offers parking, and there is very limited parking along the road. Use extreme caution if you park on the roadside and walk.

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