With the onset of Prohibition in the United States, winemaking ceased at the Chateau and in the period that followed Tubbs sold grapes but did not make wine.
In 1958 the Tubbs family sold the Chateau to Yort Wing Frank, a Chinese electrical engineer, and his wife Jeanie, who were looking for a retirement home. The Franks created a garden in the style of their homeland, and excavated Jade Lake. The Chinese garden is a popular spot for picnics, although access is now limited to members of the Chateau wine club.
In 1968, Lee and Helen Paschich bought the property, and brought in as partners lawyer James L. Barrett and property developer Earnest Hahn. Barrett replanted the vineyard and installed winemaking equipment in the historic buildings and it began producing wines again in 1972, with Mike Grgich employed as winemaker. Four years later, the Chateau Montelena 1973 Alexander Valley Chardonnay won first place in the "Judgment of Paris" wine competition. A bottle of that vintage is in the Smithsonian National Museum of American History.
In July 2008 it was announced that Michel Reybier, owner of Bordeaux winery Cos d'Estournel, had purchased Chateau Montelena from Jim and Bo Barret for an undisclosed sum.An executive committee, made up of Bo Barrett, managing director Greg Ralston, and the winemaker at Cos d'Estournel Dominique Arangoits, with Jean-Guillaume Prats, general manager at Cos d'Estournel as president, will oversee the 2008 vintage.