When will the proof of vaccination requirement go into effect for indoor, on-mountain quick-service restaurants? This protocol will be in effect as each mountain opens for the 2021-22 season. Related articles Which indoor, on-mountain, quick service restaurants will require proof of vaccination? Will I need a proof of a vaccination booster at some point during the season to dine indoors on-mountain? Will I need proof of vaccination to warm up inside? Which resorts will have limited lift tickets during December 25-January 2, January 14-17, and February 18-27? Which vaccinations will be accepted?