And why does the lake level fluctuate, you ask? Because earthquakes are common in this region. Just little earthquakes, but those who have studied Mountain Lake believe that the joints between the sandstone formations are loose and that they shift to open and close the drain at the north end. On top of that is a 30-year trend of declining precipitation, which affects the 60 springs that feed the lake, many of which pop up between the Martinsburg and Juniata formations, on the south end.
I was just trying to punctuate the same point you made and ensure that it was clear that it is not climate related.