Firehole Spring, Firehole Lake Drive, Yellowstone National Park, UNESCO World Heritage Site, Wyoming, United States of America, North America

Firehole Spring, Yellowstone National Park, UNESCO World Heritage Site, Wyoming, United States of America, North America

Firehole Spring, Yellowstone National Park, UNESCO World Heritage Site, Wyoming, United States of America, North America

Firehole Spring, Yellowstone National Park, UNESCO World Heritage Site, Wyoming, United States of America, North America

Firehole Spring in Lower Geyser Basin, Yellowstone National Park, Wyoming, USA

Tourists at Firehole River, Yellowstone National Park, Wyoming, USA

View over Firehole River, Geyser Hill, Upper Geyser Basin, geothermal springs in Yellowstone National Park, Wyoming, United States of America, USA

Fountain Paint Pots, mud pots, Firehole Lake Drive, Lower Geyser Basin, Yellowstone National Park, Wyoming, United States of America, USA

Runoff from Excelsior Geyser into Firehole River, Midway Geyser Basin, colored thermophilic bacteria, microorganisms, geysers, hot springs, Yellowstone National Park, Wyoming, United States of America, USA

Outlet of the Excelsior Geyser in Firehole River, Midway Geyser Basin, colourful thermophilic bacteria, microorganisms, geysers, hot springs, Yellowstone National Park, Wyoming, United States of America, USA

Steaming geothermal springs and geysers, Firehole River, Midway Geyser Basin, Yellowstone National Park, Wyoming, United States of America, USA

Runoff from Excelsior Geyser into Firehole River, Midway Geyser Basin, colored thermophilic bacteria, microorganisms, geysers, hot springs, Yellowstone National Park, Wyoming, United States of America, USA

Steaming geysers and hot springs, Fairy Creek, Firehole Lake Drive, Lower Geyser Basin, Yellowstone National Park, Wyoming, United States of America, USA

Colored thermophilic bacteria, outlet of the Cliff Geyser, Firehole River, Black Sand Basin, Upper Geyser Basin, Yellowstone National Park, Wyoming, United States of America, USA

Geyserite cone of the White Dome Geyser, Firehole Lake Drive, Lower Geyser Basin, Yellowstone National Park, Wyoming, United States of America, USA

Creek and pool in Biscuit Basin, Yellowstone National Park, Wyoming.

Sapphire Pool in Biscuit Basin, Yellowstone National Park, Wyoming.

Black Opal Pool in Biscuit Basin, Yellowstone National Park, Wyoming.

Sapphire Pool in Biscuit Basin, Yellowstone National Park, Wyoming.