Old Faithful

The story behind the place

Old Faithful is one of Yellowstone’s best-known geysers. Water supplied by rain and snow seeps underground, where heat and a constricted natural plumbing system create the conditions for eruptions. Park staff study the relationship between eruption duration and the following interval to make predictions. The name does not mean a perfectly fixed timetable: the intervals change, and the geyser is neither Yellowstone’s largest nor its most regular.

Find Old Faithful on the map, record the discovery in your travel journal and continue exploring nearby places.