Here we go...this is good info for Ikon pass holders. Ikon is keeping a running list of which resorts will and will not require reservations for passholders.
https://www.ikonpass.com/en/reservations
So far in the northeast, Loon and Windham are the only "Yes" ones (but they do have the footnote for K and Pico that those require parking reservations).
https://www.ikonpass.com/en/reservations
So far in the northeast, Loon and Windham are the only "Yes" ones (but they do have the footnote for K and Pico that those require parking reservations).