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Making America's Best Idea Even Better
Yellowstone National ParkStunning views of Minerva Terrace are located at Mammoth Hot Springs.
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Yellowstone National Park
Fumaroles and How They Work
A fumarole emits a jet of hot steam in Porcelain Basin.

Black Growler Steam Vent
Norris Geyser Basin

Fumaroles, or steam vents, are hot springs with a lot of heat, but so little water that it all boils away before reaching the surface. At places like Roaring Mountain, the result is a loud hissing vent of steam and gases.
Roosevelt Arch at Yellowstone's North Entrance  

Did You Know?
The Roosevelt Arch is located at the North Entrance to Yellowstone National Park. The cornerstone of the arch was laid by President Theodore Roosevelt.

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Last Updated: July 26, 2007 at 17:40 EST