150 years
I don't normally care much for anniversaries, but here's just a quick note that it was 150 years ago on 1870 Sep 18 that a number of geysers were named, including Old Faithful, Beehive, and Grotto.
Then again, get ready for the hype for 2022 March 01, which fortunately, will be at a time when the park will be mostly shut down.