National Park Service LogoU.S. Department of the InteriorNational Park ServiceNational Park Service
National Park Service: U.S. Department of the InteriorNational Park Service Arrowhead
 
 
Find a National Park Near You
Yellowstone National Park Bear walking on horizon as sun sets.
view map
text size: largest larger normal
printer friendly
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 the hottest hydrothermal features in the park. They have so little water that it all flashes into steam before reaching the surface. At places like Roaring Mountain, the result is a load hissing of steam and gases.

You are exiting the National Park Service website

Thank you for visiting our site.

You will now be redirected to:

We hope your visit was informative and enjoyable.
Disclaimer Accessibility Privacy Policy FOIA Notices USA.gov

Last Updated: August 23, 2011 at 12:54 MST