Old Faithful is a famous cone geyser in Yellowstone National Park, known for its predictable eruptions every 60 to 110 minutes, reaching heights of 100 to 180 feet and lasting 1.5 to 5 minutes, ejecting thousands of gallons of boiling water. Located in the Upper Geyser Basin, it symbolizes Yellowstoneβs geothermal activity and was named in 1870 due to its regularity. It is powered by underground volcanic heat and remains a key attraction, with a nearby visitor center providing eruption predictions. Old Faithful has been a central feature of Yellowstone since the parkβs establishment in 1872.