Interval irregular. Duration 30 minutes to 3 hours. Height 40 feet. Temperature 191.8°F
A. C. Peale, geologist for the 1872 Hayden Expedition, named this feature for its cliff-like wall of geyserite formed around the crater and for its location on the edge of Iron Creek.
An indication of a pending eruption is that the crater nearly fills with boiling water.
As the eruption begins, jets of water explode through the pool 15 to 40 feet high.
This is accompanied by a tremendous amount of steam.
The eruption reaches its highest point the first half hour and gradually subsides until the crater empties.
The interval is irregular, lasting between a half hour to 18 hours, and there may be weeks or even years of dormancy.
When it is active there are usually one or two eruptions a day.