Eruptions[edit]
File:OldFaithful.ogg

16-second video clip of an eruption
Eruptions can shoot 3,700 to 8,400 US gallons (14,000 to 32,000 L) of boiling water to a height of 106 to 185 feet (32 to 56 m) lasting from 1.5 to 5 minutes. The average height of an eruption is 145 feet (44 m).[7] Intervals between eruptions can range from 45 to 125 minutes, averaging 66.5 minutes in 1939,[8] slowly increasing to an average of 90 minutes apart today.[9] The time between eruptions has a bimodal distribution.

More than 137,000 eruptions have been recorded. Harry Woodward first described a mathematical relationship between the duration and intervals of the eruptions (1938).[8][10] Old Faithful is not the tallest or largest geyser in the park; that title belongs to the less predictable Steamboat Geyser.[4] Its popularity is more likely due to the small eruption window and high frequency.