Recent visitors gushed over the rainbow array of the spring ... Access to the Grand Prismatic Spring is included in Yellowstone's seven-day pass ($35) and there are no set hours of operation.

focusing on Yellowstone's geothermal features. While wide-eyed enthusiasts come from far and wide to see the dazzling rainbow colors of the Grand Prismatic Spring or dependable bursts of Old ...

These marvels are a must-see when you're in Yellowstone, especially its largest, rainbow-colored Grand Prismatic Spring. But don't be fooled by these stunning hot springs—they're extremely ...

As the headquarters of Yellowstone National Park, the Mammoth Springs Historic District is also home to historic buildings, including structures that date back from the Fort Yellowstone days ...

Editor’s Note: This story accompanies the May 2016 issue of National Geographic magazine, devoted entirely to America’s first national park. Find more at natgeo ...

Their images helped influence Congress to make Yellowstone the first National Park. Smithsonian American Art Museum Rainbow over the Grand Canyon of the Yellowstone Smithsonian American Art Museum Old ...