White Dome Geyser is a geyser located in the Lower Geyser Basin in Yellowstone National Park in the United States.
White Dome is a conspicuous cone-type geyser located only a few feet from Firehole Lake Drive, and accordingly, seen by many visitors to the park as they wait for eruptions of nearby Great Fountain Geyser. Its 12-foot-high geyserite cone is one of the largest in the park. Its eruptions are unpredictable, but generally occur with intervals ranging from 15 minutes to 3 hours. Intervals between 20 and 35 minutes are most common. Eruptions typically last 2 to 3 minutes and reach heights of about 30 feet (9.1 m), the maximum height being attained early in the eruption. As usual for cone-type geysers, the play is continuous for most of the eruption's duration, and begins and concludes with a brief steam phase intermixed with liquid spray.
Although it is overshadowed in eruptive height and power by Great Fountain Geyser, White Dome Geyser is a significant feature that was used as an emblem by the old Yellowstone Library and Museum Association, now the Yellowstone Association. The thermophilic bacterium Thermus aquaticus, important because it produces an enzyme used in polymerase chain reaction laboratory procedures central to modern molecular biology, was first isolated from Mushroom Pool, a non-eruptive hot spring a few hundred feet from White Dome Geyser.
White Dome is the largest member of the "White Dome Group," a cluster of features bisected by Firehole Lake Drive that includes at least six other geysers as well as several non-eruptive springs. Gemini Geyser and Crack Geyser, across Firehole Lake Drive from White Dome, also erupt comparatively frequently, and can be observed from the parking area for White Dome, while the other members of the White Dome Group erupt only rarely, are difficult to see from the road, or both.