• A bull elk bugles in Yellowstone National Park

    Yellowstone

    National Park ID,MT,WY

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  • Construction Work To Result In Yellowstone Road Closures After Labor Day

    Two sections of Yellowstone’s Grand Loop Road will be closed due to construction after the Labor Day holiday weekend. Travel between some points will involve long detours and significantly longer than normal travel times. More »

How Geysers Work

Animated GIF showing how geysers work
 

For geyser to occur there must be heat, water, and a plumbing system. A magma chamber provides the heat, which radiates into surrounding rock. Water from rain and snow works its way underground through fractures in the rock.

As the water reaches hot rock it begins to rise back to the surface, passing through rhyolite, which is former volcanic ash or lava rich in silica. The hot water dissolves the silica and carries it upward to line rock crevices. This forms a constriction that holds in the mounting pressure, creating a geyser's plumbing system.

As superheated water nears the surface, its pressure drops, and the water flashes into steam as a geyser. Hot springs have unconstricted plumbing systems.

Did You Know?

Seventh Cavalry Ensignia Pin.

Prior to the establishment of the National Park Service, the U.S. Army protected Yellowstone between 1886 and 1918. Fort Yellowstone was established at Mammoth Hot Springs for that purpose.