We must have narrowly missed seeing Old Faithful go off the time before we got there as we waited for around an hour and a half before it wen again which is supposedly about the longest it takes (on average) to start up again. We had already seen a number of other smaller geysers that we didn't have to wait for, and that we could get much closer to, so while it was neat, Old Faithful wasn't as impressive as I thought it might be.