Yellowstone’s Old Faithful

Old Faithful erupts more frequently than any of the other big geysers in Yellowstone National Park. Its average interval between eruptions is about 76 minutes, varying from 45 – 110 minutes. An eruption lasts 1 1/2 to 5 minutes, expels 3,700 – 8,400 gallons (14,000 – 32,000 litres) of boiling water, and reaches heights of 106 – 184 feet (30 – 55m). It was named for its consistent performance by members of the Washburn Expedition in 1870. Although its average interval has lengthened through the years (due to earthquakes and vandalism), Old Faithful is still as spectacular and predictable as it was a century ago.