Old Faithful

Contrary to popular belief, Old Faithful Geyser has never been either the largest or the most regular of geysers overall, yet it has been the most regular and frequent geyser that erupts to a height of more than 100 feet. The average time between eruptions ranges from about 66 to 80 minutes.

Steamboat, in the Norris Geyser Basin, is the world's tallest active geyser. Eruption frequencies for this geyser and others in the basin change fairly often, especially in response to seismic activity.