Did you hear? Giantess erupted!

Yellowstone geysers have various intervals.  Some erupt every few second or minutes;  some have intervals on the order of hours;  some take a few days between performances, and some are totally unpredictable, but they do go off with enough frequency to be observed.

Then there are the prima donnas;  the big stars that only give an occasional show.  Chiefest among these are Steamboat, in the Norris Geyser basin, which recently erupted for the first time in eight years;  Giant, in the Lower Geyser basin, which apparently goes decades before taunting the public with an active period of a couple years or so (during which it is maddeningly interesting to wait for);  and the fickle Giantess, also in the Lower Geyser Basin which can erupt several times a year -- or not at all.  "Not at all" was the theme for the last couple of years, apparently, until it finally awakened from one of its longest periods of quiescence and fired off some fountains.

Yellowstone's Giantess Geyser erupts for more than 40 hours

At least it had the decency to get started during the day.