To answer the main query, POWDR Corporation, a privately held business based in Park City, Utah, owns Killington Ski Resort. In order to improve the visitor experience, POWDR Corporation purchased the resort in 2007 and has subsequently made a number of modifications, including upgrades to the lifts and snowmaking.
Whether Vail owns Sugarbush is a related query. The answer is negative; Sugarbush is not owned by Vail Resorts. Summit Ventures NE, LLC is the only owner and operator of the resort. Skiing, snowboarding, and other winter sports are available in Vermont at Sugarbush.
Regarding Mammoth, Mammoth Mountain Ski Resort was indeed purchased by Vail Resorts in 2017. Mammoth Mountain Ski Area, June Mountain, and Snow Summit Mountain Resort were all acquired. Numerous other well-known ski resorts are also owned by Vail Resorts, including Whistler Blackcomb in British Columbia, Park City in Utah, and Vail, Beaver Creek, and Breckenridge in Colorado.
Last but not least, Mammoth Mountain is frequently misunderstood to be an active volcano. This is untrue, though. Despite being a sizable volcanic dome, Mammoth Mountain has not erupted in more than 57,000 years and is thought to be dormant. The hot springs in the region are a result of geothermal activity on the mountain.
In conclusion, Mammoth Mountain Ski Resort is owned by Vail Resorts, while Sugarbush is independently owned and operated and Killington Ski Resort is owned by POWDR Corporation. Furthermore, Mammoth Mountain is a dormant volcanic dome with geothermal activity rather than an active volcano.