(Rick Egan | The Salt Lake Tribune) Skiers are required to wear face coverings they ski at Park City on opening day, Friday, Nov. 20, 2020. Vail Resorts, which own Park City Mountain, and Alterra Mountain Company have both been sued by pass holders for cutting short the 2019-20 ski season because of the COVID-19 outbreak. Alterra reached a settlement earlier this year and began issuing credits to customers this week.