If you visit Yellowstone National Park, then you must go to the Grand Prismatic Spring, which is the largest hot spring in the US, and the third largest in the world, after Frying Pan Lake in New Zealand and Boiling Lake in Dominica. Yellowstone is home to thousands of thermal features and Grand Prismatic Spring is one of them, it is about 250 by 300 feet in size and is 160 feet deep. The spring discharges an estimated 560 US gallons of 160 °F water per minute. It is located in the Midway Geyser Basin. In 1871, it was noted by geologists working in the Hayden Geological Survey, and named by them for its prominent coloration. Because its colors match the rainbow dispersion of white light by an optical prism: red, orange, yellow, green, and blue.
The first records of the spring are from early European explorers and surveyors. In 1839, a group of fur trappers from the American Fur Company crossed the Midway Geyser Basin and made note of a "boiling lake", most likely the Grand Prismatic Spring, with a diameter of 300 feet. In 1870 the Washburn-Langford-Doane Expedition visited the spring, noting a 50-foot geyser nearby Excelsior. The gorgeous vivid colors in the spring are the result of pigmented bacteria in the microbial mats that grow around the edges of the mineral-rich water.
The bacteria produce colors ranging from green to red; the amount of color in the microbial mats depends on the ratio of chlorophyll to carotenoids and on the temperature of the water which favors one bacterium over another. In the summer season, the mats likely to be orange and red, while in the winter season the mats are generally dark green. The center of the pool is sterile due to intense heat. The deep blue color of the water in the center of the pool results from the intrinsic blue color of water, itself the result of water's selective absorption of red wavelengths of visible light. However this effect is responsible for making all large bodies of water blue, it is mainly penetrating in Grand Prismatic Spring because of the high purity and depth of the water in the middle of the spring.
Well, The Grand Prismatic Spring is truly 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 bright rainbow ring of colors. The Grand Prismatic Spring is one of America's most striking 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. Without any doubt this is one of the coolest things to see if you're in Yellowstone, absolutely stunning, definitely worth a visit. Because the springs have some beautiful colors surrounding it, which you’ve often see in your life. This is truly a breathtaking place and even sunlight is a huge part in seeing the vivacity of the colors, wait out the clouds if you can!