The season is highly weather dependent, but I'd say on average, they open a week before Christmas and close towards the end of March. I've seen them open into April if snow allows too. Last year was a really bad season and they opened January 8th and closed March 13th. The year before, they opened December 21st and closed March 29th, and reopened for April 1st, 4th and 5th. The year before that, they opened December 14th and closed April 1st, and reopened for April 5th.
The season was 10 weeks in the absolute worst season I've been alive for. Even 06-07 had a few decent storms near the end. 11-12 was actually ok for mountains with lots of snowmaking. It was just labeled a bad season because of skiers wanting natural snow and the 80 degree 3 week meltdown at the end.
What high school does your daughter go to?
I've lived in New York my entire life.