Grand Prismatic Spring in Yellowstone National Park is the largest hot spring in the United States and the third largest in the world. It’s almost 370 feet in diameter and 121 feet deep. Its vibrant color is the result of thermophilic (heat loving) organisms living along the edges of the steaming pool. This unique ecosystem is delicate and dangerous. To protect it and yourself, stay on the boardwalks when visiting and take the #YellowstonePledge: http://ift.tt/2j70UN7. Photo by Manish Mamtani (http://ift.tt/18oFfjl).
Sig Nordal 