The only clear memory I thought I had from visiting Yellowstone as a child was of Old Faithful. As usual my memory was false. Not only was the picture in my head nothing like the famous geyser, I didn’t come across any spot in the whole park that seemed to match the vision in my head. This is what memory does, however. It adjusts and interprets every time it is replayed, until what you have bears no resemblance to what you saw.
This happens a lot with Old Faithful. Not only is it the most famous and well known feature of Yellowstone, it is the most misunderstood and misinterpreted. I went on a ranger Hill Walk through the Old Faithful area, and the ranger said they overhear the strangest claims about the geyser. Some say it’s the tallest geyser in the world (not true). Some say it sprays out more water than any other feature in the park (also not true). But most often people say it goes off every ten minutes. This isn’t remotely true and it never has been.
The real reason we flock to Old Faithful is a mixture of awe and predictability. There are certainly more impressive geysers in the park, but they go off at strange times, and sometimes with no warning at all. The ranger stations track all of the most predictable geysers, and they show time ranges of plus or minus 4 hours with 75% accuracy. Most people don’t want to sit in front of a geyser for eight hours with a 25% chance nothing will happen.
There are more frequent geysers, some that go off every 10-20 minutes or so. However these are small, bubbly things. I saw several of those little eruptions when I was in the park. They may be fun to watch, but they won’t draw a crowd.
In contrast, Old Faithful is impressively tall, shooting up several stories into the air. And the rangers are able to predict the next eruption with pretty good accuracy and plus or minus only 10 minutes. The eruptions usually occur every 90 minutes, meaning any tourist who happens to drive by won’t have to wait long for the next show. It’s possible to plan your day around seeing the next eruption. This is so common that right after each eruption the rangers at the Old Faithful station put out a message to all the ranger radios announcing the next predicted blast.
My favorite fact I learned about Old Faithful was that it used to be even more frequent. When it was first seen by settlers, it erupted every 60 minutes. But Yellowstone is still a changing force, and a mysterious one at that. Sometimes features change in the park, and even the geologists and volcanologists can’t say why. But something shifted the pipes below Old Faithful, and now you’ll only see a 60 minute window if the last eruption was especially small.
Between the Hill Walk and my lunch break, I was in the Old Faithful area for some time. I saw an eruption early in the day, and thought I might catch a second one before I had to leave for the next ranger walk up near Black Sand Basin. I figured I could make the drive in ten minutes, which meant I had to leave by 12:20PM. The next eruption was due for 12:08, so I was sure to see it before I had to leave. That is, I would see it if the prediction was correct. I stood with the other tourists past 12:08, then past 12:18. After waiting as long as I could, I jumped in my car and rushed over to Black Sand Basin. Right as the Black Sand ranger was preparing to start his talk I heard the announcement come out of his radio, “Next Old Faithful eruption predicted for 1:57PM.” If had happened almost 20 minutes late.
The rangers can predict Old Faithful correctly 90% of the time. Wait around long enough and you’re bound to find the other 10%.