sentences:  In 2017, Mammoth Resorts announced its sale by Starwood to a partnership of Aspen Skiing Company and KSL Capital Partners, known as Alterra Mountain Company.For decades, Snow Summit and Goldmine Mountain operated independently of one another, less than two miles apart.In 1988, S.K.I., a major ski area operator, bought Goldmine, changed its name to Bear Mountain, and invested millions of dollars in improvements that enhanced its competitive position against Snow Summit.