Yes, actually it was open last year but there was an error on the list they handed out when you got there. Seems like the listing from allearsnet.com had the same mistake.
In fact, when we were there we made sure to ride it before 7 p.m. and mentioned it to the CM standing there. He said it would be open late, since he was working until midnight. He was right, it was open (when it wasn't rainining, that is)
I'll edit my first post.