 In August 1964, the Mountain Dew brand and production rights were acquired from Tip by the Pepsi-Cola company, and the distribution expanded across the United States and Canada.Between the 1940s and 1980s there was one variety of Mountain Dew, which was citrus-flavored and caffeinated in most markets.Diet Mountain Dew was introduced in 1988, followed by Mountain Dew Red, which was introduced and discontinued in 1988.