Old Faithful Geyser: Yellowstone's Iconic Eruption and Must-See Spectacle

Though not the tallest or most predictable geyser in Yellowstone National Park, Old Faithful stands as the park's enduring symbol and a perennial favorite among visitors. Approximately every 90 minutes, it erupts with around 8,000 gallons of water—equivalent to 150 bathtubs—reaching heights of up to 180 feet. For the best experience, observe from multiple viewpoints: the benches beside the geyser, the upper balcony of the historic Old Faithful Inn, or our top recommendation, the distant overlook on Observation Point.

Named by the Washburn expedition in 1870 for its reliability, Old Faithful erupted roughly every hour for over 75 years. Today, the average interval is 90 minutes and gradually lengthening, historically ranging from 45 to 110 minutes. Eruptions typically last about four minutes, with water temperatures around 204°F (95°C) and steam reaching 350°F (176°C). Longer eruptions mean extended recharge times. Park rangers accurately predict eruptions within 10 minutes about 90% of the time—and contrary to myth, it has never erupted precisely on the hour.

A practical tip for timing your visit: the growing crowd around the geyser is a reliable inverse indicator of time until the next eruption—the more visitors, the sooner it will happen.

While awaiting the show, reflect on sustainability: the boardwalk you're on is constructed from roughly three million recycled plastic water bottles.