Yellowstone’s most famous feature is almost inarguably Old Faithful Geyser. In fact, the eruptive icon is practically synonymous with the park itself.

When the Washburn Expedition discovered Old Faithful in the 1870s, they dubbed it "Eternity's Timepiece" in honor of its regular eruptions. And, like a finely tuned geologic machine, Old Faithful has mostly stayed on schedule even after 150 years.

Today, it remains one of the most well-known and dependable geysers in the world, and it’s likely to be the highlight of every visitor's trip to Yellowstone.

old faithful geyser exploding Photo from Unsplash by Emily Campbell

What is Old Faithful?

Old Faithful is a geyser, which is the world’s rarest type of hydrothermal feature. Geysers, unlike hot springs, blast hot water into the air on a regular basis in what’s known as an “eruption cycle.” The eruption cycle of Old Faithful is part of what makes it so unique: its next eruption can be timed to within 10 minutes of accuracy!

But how does it work? Well, like most of Yellowstone's geothermal features, Old Faithful sits atop a massive volcanic caldera, also called a crater. This caldera is about 30 x 45 miles across. To give you some perspective, that’s nearly the size of Rhode Island! People have popularly nicknamed Yellowstone's caldera a "supervolcano" due to its immense size.

Hotspots, or areas where hot material from the mantle or core rises towards the crust, perforate this supervolcano. This magma heats the water that seeps into underground reservoirs, increasing the temperature and pressure.

Old Faithful is one such reservoir. The majestic geyser holds superheated water to well above boiling point, much like a pressure cooker. Its only way out is through a thin pipe or stem through the rock to the surface. As small amounts of water escape, the system becomes more and more unstable. Eventually, the pressure in the reservoir drops enough, and—whoosh!—the reservoir’s contents gush out, with water exploding as high as 184 feet into the air.

This epic eruption can last up to 5 minutes and can occur anywhere from every 58 minutes to every 127 minutes. Lucky for us, it’s easy to witness this awesome spectacle for ourselves.

RELATED: Why is it Called Old Faithful?

Where is Old Faithful?

Old Faithful is the most well-known geyser in Yellowstone's Upper Geyser Basin. This geyser basin in Yellowstone's southern loop is home to over 100 geothermal features, and while Old Faithful is the main attraction, you won't want to miss out on the other geothermal features, either.

There are approximately 5 miles of looping boardwalks to explore along the Old Faithful area, including the 1.6-mile (there and back) Observation Point Trail, which provides a less crowded vantage point for viewing Old Faithful. You can find more information on these and other nearby trails in our hiking guide.

If hiking isn’t on the agenda, don’t despair. The viewing deck for Old Faithful is easily accessible and has dozens of benches where you can wait for the show. Signs on the deck inform visitors of the time until the next eruption.

To reach the deck, visitors will park at the Old Faithful Visitor Center or Old Faithful Lodge, both down Old Faithful Road. The road is about 16 miles west of West Thumb Geyser Basin or about 18 miles south of Madison Junction—both about a 30-minute drive.

RELATED: Six Haunted National Parks

Tips to Visit Old Faithful

More than the "do's," the best tips for Old Faithful are the "don'ts."

Don’t arrive at Old between noon and 2 p.m. That’s the busiest part of the day, and both the parking lot and the viewing deck will be very crowded. It’s far better if you can arrive before 10 a.m. or after 6 p.m.

Another don’t: don’t try to hop back in your car right after the eruption. You’ll be leaving at the same time as everyone else. Instead, consider exploring the visitor center or the rest of the Old Faithful Loop for 20 or 30 minutes. In fact, regardless of your arrival or departure time, I strongly recommend that you visit the Visitor Center. With that and your handy Shaka Guide, you'll be an Old Faithful expert in no time!

Finally, a do: If you are there at a highly busy time, consider hiking to Observation Point instead. There will be fewer people back there, and it offers a unique perspective. Just check the sign to be sure you have plenty of time to make the hike before the next eruption!

The Old Faithful Schedule

Old Faithful usually erupts every 68 to 94 minutes. So, in the worst-case scenario, you'd have to wait just over an hour and a half. With over 20 eruptions every day, your odds of a short wait are pretty good!

The National Park Service regularly updates the Old Faithful eruption schedule. Check the schedule if you have limited time or need to arrive at a specific time of day.

Word of advice: try to check the schedule before entering the park. You may not have enough signal to load the page otherwise.

How Accurate are the Old Faithful Predictions?

The NPS is more than 90% accurate within a 10-minute margin in its predictions. These predictions are based on factors such as the length and volume of water discharged by previous eruptions.

It might surprise you to learn that Old Faithful's eruption pattern has changed over time. Before the 1959 Hebgen Lake earthquake, Old Faithful erupted more frequently. In fact, contrary to popular belief, Old Faithful has never erupted on the hour and is not considered the most consistent of Yellowstone National Park's geysers. Others, like Daisy Geyser, can be predicted with greater accuracy.

That's not to diminish the wonder of Old Faithful; it's well worth the trip! But I'd be remiss if I didn't mention that there are numerous other geysers in Yellowstone that you should see. Be sure to browse our Biggest Best Geyser Guide where we blow the lid off of the must-sees, should-sees, and maybe skips in Yellowstone.

Final Advice

Yellowstone is a big park, and major features like Old Faithful can draw crowds from far and wide. It can be difficult to plan everything, especially when you’re trying to avoid the park’s busiest times. Fortunately, we’re here to help!

Along with our expertly crafted audio tours, we have several detailed guides on nearby hikes, itinerary suggestions, and know-before-you-go advice. Be sure to browse our other helpful articles before you head out on your Yellowstone adventure!

Ready to take the tour? Check out Shaka Guide's Yellowstone National Park Tour!

We hope that we’ve given you all the information you need to make the most of your day. Your vacation is extremely important to us so if you have any questions feel free to reach out at aloha@shakaguide.com.

For more detailed information to help you plan, check out our Yellowstone National Park Itinerary and Know Before You Go article.

Like this article? Share it on Pinterest!