We have until 4/20. Thats when I celebrate summer starting and winter being over.
closing day at mt snow last year was 4/19, killington was even later. I had a day that was 90 degrees sometime in late april (4/26 or 27 I think) last year and they had a park setup and it was an awesome day, with some great vibes. And I skied every weekend for almost another month, setting up rails on the inferno jumps, or whatever it took. Some of my best days were in the spring when the mountains were closed. You always have the memorial day rail jams to look forward to at stowe and Mt snow. I didnt go to mt snow last year but stowe was so much fun