Grotto.

     We went from the spectacular to the formidable: from Riverside to Grotto. (more on Grotto here.) The interval between eruptions can be seven hours to a day, so, again, we were fortunate to catch it. It's a big one, and can spout 700,000 gallons of water in a single eruption lasting usually one to two hours. That's as much water as Old Faithful spouts in three days.


 
     Waiting; that's a not-altogether friendly geyser-gazer in the foreground.



    And off she goes! (I've decided geysers are feminine.)


   
     From another angle:




     It's a maelstrom.