Firehole River at Midway Geyser Basin in the Yellowstone National Park, Wyoming, USAYellowstone National Park was founded on March 1, 1872, and is considered the world’s first national park. It is loc
The Firehole River flowing past the steaming thermal pools of Midway Geyser Basin. The river is warmed by the runoff from dozens of thermal features — unusual swimming is technically allowed in a short stretch near Firehole Canyon. © Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons

More on this story