Explorers in the Washburn Expedition named Old Faithful in 1870 because of its consistent performance of eruptions. Old Faithful erupts more frequently than any of Yellowstone’s other large geysers, but it is not the largest nor the most regularly erupting geyser in the park. Its average interval between eruptions is between 60 minutes and 91 minutes. Usually Old Faithful eruptions last 1.5 to 5 minutes, and it projects 3,700 - 8,400 gallons of boiling water up into the air between 106 and 184 feet high. The 7.3 magnitude earthquake in 1983 shook the land so much that it altered the plumbing of several geysers in Yellowstone, including Old Faithful. Now, it erupts less frequently and more irregularly. However, Old Faithful is still as grandiose and basically as predictable as it was a century ago.
