Old Faithful Geyser
Over the years, the difference in time has increased, which may be the result of earthquakes changing underground water levels. These disruptions have made the earlier relationship inaccurate, but have made Old Faithful more predictable. With an error of 10 minutes, Old Faithful will erupt 65 minutes after an eruption lasting less than 2.5 minutes or 92 minutes after an eruption lasting more than 2.5 minutes. The reliability of Old Faithful is because it is not connected to any other thermal features of the Geothermal areas of Yellowstone| Upper Geyser Basin]].