Bulger Geyser, Geyser in Upper Geyser Basin, Yellowstone National Park, United States

Bulger Geyser is a fountain-type geyser in the Upper Geyser Basin of Yellowstone National Park, Wyoming, 200 feet (61 m) south of Grand Geyser. It erupts frequently, mostly in minor bursts lasting seconds, with infrequent major eruptions lasting up to 12 minutes. Both types produce vigorous bursting 1 to 12 feet (0.3 to 3.5 m) high.

Bulger Geyser sits in the Upper Geyser Basin, about 60 metres south of Grand Geyser. Its fountain-type eruptions were described in early surveys of the basin's thermal features, and later observers recorded both brief minor bursts and rare major plays lasting up to 12 minutes.

Scientists and geologists study Bulger Geyser as part of their research into the patterns and behaviors of thermal features in Yellowstone.

The geyser sits in a thermal area with hot water and steaming surfaces, so staying on marked trails keeps you safe. Early morning visits offer the best viewing conditions with fewer visitors and good lighting.

Bulger Geyser sits about 200 feet (61 m) south of Grand Geyser, and its bursts reach only 1 to 12 feet (0.3 to 3.7 m) high, so visitors often walk past it while watching its larger neighbour.