See the context of this sign.

Castle Geyser

The massive cone is a sign of old age. Eruption
after eruption, probably for thousands of years,
scalding water has deposited this silica mineral
formation. By contrast, Old Faithful's fledgling
cone may be only a few hundred years old.

Castle Geyser has dramatically changed its
surroundings. By flooding the area with hot,
silica-rich water, the geyser has devoured part
of a pine forest and turned it into a thermal
desert. Tree skeletons are entombed within
the cone.

Castle Geyser's eruptions are predictable; two
per day are typically recorded.

Thomas Moran painted this watercolor in 1872.
Vandalism has since destroyed some of Castle
Geyser's original symmetry.

Walter Trumbull, a member
of the Washburn expedition,
sketched Castle Geyser in 1870.

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