Geography: Old Faithful, The Jewel Of ___________________________ In Calistoga, California, Is Not As Dependable As It Used To Be. Because Of Vandalism And Age-Old Geological Shifts, The World's Largest Geyser Is Slowly Losing Its Reputation For Erupting Like Clockwork. In 1970, The Average Time Between Eruptions Of The 126-Year-Old Geyser Was 66 Minutes. The Average Today Is About Once Every 77 Minutes, Or 18 Times A Day Instead Of 21. The Geyser's Power Hasn't Diminished, However