Old Faithful is only one of a few hundred geysers in the park. It’s not the tallest geyser. Other geysers erupt longer or more frequently. So why is Old Faithful the most famous?
First of all, it’s one of the few predictable geysers. Geysers are very rare and predictable geysers are even rarer. Most geysers don’t have a discernable pattern of behavior but a few do. Old Faithful is rather tall, shooting water 120’ in the air. Many visitors are able to see it because it erupts several times each day and is predictable to within less than half an hour.
Why is its pattern of behavior so regular? We think the fact that it is set apart from many other thermal features means it doesn’t have to share its plumbing system.
In areas where there are several features close to one another like on Geyser Hill, they’re often connected so a change in one affects the others. Because Old Faithful is separate, it isn’t easily influenced by the activity of other geysers and springs.
We do know that Old Faithful has been faithful at least since 1870 when it was named for its regularity. It’s one of the features that has made Yellowstone a destination for millions. In fact, become a symbol of the park itself and is an American icon.