Old Faithful was named by the first official expedition to Yellowstone, the Washburn Expedition of 1870. They were impressed by its size and frequency. Old Faithful erupts every 35 to 120 minutes for 1 1/2 to 5 minutes. Its maximum height ranges from 90 to 184 feet.

It is not the biggest or the most regular geyser in Yellowstone but it is the biggest regular geyser. Furthermore, it has been erupting in nearly the same fashion throughout the recorded history of the park. Through the years, it has become one of the most studied geysers. One result of this close observation is that the Park Rangers are able to predict its eruptions fairly accurately. This makes Old Faithful geyser one of the easiest geysers in Yellowstone to see.
 Old Faithful is deceiving. The benches around the geyser are over 300 feet from the geyser but with nothing to judge the distance by, I rarely realize just how big the geyser is until I get further away. Personally, I like the view from Geyser Hill. As with any geyser, watch the wind direction or you may only see steam.