White Dome Geyser erupts from one of the largest cones in Yellowstone National Park. Based on the size of the highly eroded cone and the slow rate at which sinter is deposited, it appears that a spring has been active here for a very long time. Amazingly, White Dome sits atop an even older hot spring formation.
White Dome is a cone-type geyser erupting for durations of about 2 minutes from a vent that is said to be 5 inches by 7 inches. The 20-30' tall eruptions coupled with the 20' tall cone make for a pretty display. Unfortunately, White Dome is very erratic. Intervals often range from 15 minutes to 3 hours.
Because of this erratic behavior, most people don't wait at White Dome to see an eruption. Instead they see an eruption from a distance while while waiting at Great Fountain.