Natural · Wyoming
Old Faithful
Old Faithful mid-eruption. — Dietmar Rabich
Why Old Faithful Matters
The geyser whose reliable eruptions helped convince a skeptical Congress that Yellowstone's wonders were real, kickstarting the entire American national park idea.
By the Numbers
History
- Naming
- Named in 1870 by the Washburn-Langford-Doane Expedition
- Park connection
- Reports of the geyser helped establish Yellowstone as the first U.S. National Park in 1872
Geology
- Eruption interval
- Roughly every 44-125 minutes (averaging about 90 minutes)
- Eruption height
- 106-185 feet
- Eruption duration
- 1.5-5 minutes
Architecture
- Old Faithful Inn
- Built 1903-1904 by architect Robert Reamer, one of the largest log structures in the world
Science
- Prediction
- Rangers predict eruptions within about a 10-minute window using prior eruption data
Timeline
- 1870Named by the Washburn-Langford-Doane Expedition
- 1872Yellowstone is established as the first U.S. National Park
- 1904The Old Faithful Inn is completed beside the geyser
Complete History
Members of the 1870 Washburn-Langford-Doane Expedition, exploring the region that would become Yellowstone, named the geyser 'Old Faithful' for the unusual regularity of its eruptions compared to the area's many other, less predictable thermal features. Their published accounts of geysers, hot springs, and canyons in the region helped persuade a skeptical Congress and public that the reports weren't exaggeration.
In 1872, partly on the strength of accounts of features like Old Faithful, Congress established Yellowstone as the first National Park in the United States, and arguably the world, setting aside the region's geothermal wonders for public enjoyment rather than private development. Old Faithful itself erupts roughly every 44 to 125 minutes, sending water and steam 106 to 185 feet into the air for one and a half to five minutes at a time.
As tourism to the young park grew, the Northern Pacific Railroad and its partners built the Old Faithful Inn beside the geyser between 1903 and 1904. Designed by architect Robert Reamer, the massive log-and-stone building remains one of the largest log structures in the world. Today, park geologists can predict Old Faithful's next eruption within about a ten-minute window by tracking the duration of the previous one, letting visitors plan their viewing with rare confidence for a natural phenomenon.
Historic Images
Interesting Facts
- Old Faithful is not the largest or most regular geyser in Yellowstone, but is the most famous for its predictable, frequent eruptions.
- Its eruptions can reach up to 185 feet high and last as long as five minutes.
- The nearby Old Faithful Inn, completed in 1904, is one of the largest log structures in the world.
- Accounts of Old Faithful and Yellowstone's other geothermal features helped convince Congress to create the first U.S. National Park in 1872.
- Rangers can predict eruption times within roughly a 10-minute window by tracking the duration of the previous eruption.
Visiting Today
- Hours
- Grounds open 24 hours; visitor center hours vary seasonally
- Admission
- Included with Yellowstone park entrance fee
- Best time to visit
- Check predicted eruption times at the visitor center and arrive 20-30 minutes early for a good seat
- Nearby
- Old Faithful Inn, Grand Prismatic Spring, Yellowstone Grand Loop
The boardwalk loop around the geyser basin offers views of other nearby thermal features while you wait
Frequently Asked Questions
How often does Old Faithful erupt?
Roughly every 44 to 125 minutes, averaging about every 90 minutes, though the exact interval depends on the duration of the previous eruption.
Why is it called 'Old Faithful' if the interval varies?
Compared to Yellowstone's other geysers, its eruptions are unusually predictable and frequent, which earned it the name from the 1870 Washburn-Langford-Doane Expedition, even though the interval isn't perfectly fixed.
Is Old Faithful the biggest geyser in Yellowstone?
No. Several other geysers in the park erupt higher or less predictably; Old Faithful is famous for its consistency and visibility, not its size.
What is the Old Faithful Inn?
A historic hotel built in 1903-1904 next to the geyser, designed by architect Robert Reamer and considered one of the largest log structures in the world.
