Not accurate about the ski resort thing, seems Bruce Willis owns property near the resort, a quick google seach found this:
"Today, celebrities like Bruce Willis own property near Sun Valley and enjoy its quiet hospitality. The uncrowded conditions are a result of the secluded location, and the resort staff emphasizes customer service. Sun Valley offers elegance and the best accommodations, but it is also very relaxing and family-oriented. The services and meticulous maintenance at the resort qualify Sun Valley as the "Disneyland of ski resorts." The consensus is that although Sun Valley is hard to reach it is well worth the effort.
Check out Bruce Willis' club The Mint in Hailey (11 miles south of Ketchum), which offers dancing and occasional singing by Bruce Willis."