Photographs of Upper Geyser Basin, Yellowstone National Park

North of Grand Geyser, the Upper Geyser Basin Trail leaves the Sawmill Group and enters partly wooded terrain, at the margin of the more dispersed Giant Group. The next thermal feature is Economic Geyser, a regularly erupting spring early last century but largely dormant since the 1920s. Subsequent activity has largely been confined to gradual changes in temperature; the pool can heat up to near boiling, filled by clear water with no algae, or cool down so that it becomes lined by orange or brown bacteria. The pool measures six feet in diameter though the actual vent is much narrower. 20 feet beyond is the larger but equally inactive and similarly colored pool of East Economic Geyser.

Back to map of the Upper Geyser Basin

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