I'm pained to hear these "end of season" kinds of stories. I think I'd go into a serious depression if my local chairlifts stopped this early. If it helps anyone's plans for the remainder of this year, we just last week passed the halfway mark of this years' "chairlift season."
Our chairlifts usually stop sometime between Memorial Monday and the end of June so we have plenty of pow days ahead.
(Then there are those of us who don't know when to quit and keep skiing even when they stop, but that's a different story.)
Of course--Mammoth, Timberline, and a couple of others are open much later than that, so I'd suggest maybe moving?...
"Skiing: The underlying purpose of the Universe" SkiStreak.com