(Wines&Vines) - One of Napa County’s iconic Cabernet Sauvignon vintners and a founding name of Sonoma County Pinot Noir recently died a day apart from each other.

Raymond Twomey Duncan, 84, the founder of Silver Oak winery in Napa Valley, died Oct. 9 at his home in Denver, Colo. He is survived by his wife Sally, their six children and 16 grandchildren.

Walter Schug, 80, the founder of Schug Carneros Estate, died at home Oct. 10 while surrounded by his family. Schug is survived by three children.

Duncan was born in South Bend, Ind., and in 1952 graduated from the University of Notre Dame with a degree in philosophy. He joined the Marine Corps and served in the Korean War, achieving the rank of captain.

In 1958, Duncan moved to Durango, Colo., where he founded Duncan Oil and Purgatory Ski resort in the San Juan Mountains. Duncan and his family moved to Denver in 1967 to further pursue the oil and gas business. An invitation by Jack and Mary Novak, founders of Spottswoode Winery, brought him to the Napa Valley in 1970, and he was inspired to purchased land for vineyards.

By 1972, Duncan had acquired several vineyard properties in the Alexander and Napa valleys, with the goal of planting vineyards to grow and sell grapes. A chance meeting with winemaker Justin Meyer resulted in a friendship, and they founded Silver Oak “over a case of beer and a handshake.”

Silver Oak has grown to become a leading brand in the U.S. wine industry, and today the winery is managed by Duncan’s sons, Tim and David Duncan. The Duncan family founded Twomey Cellars in 1999, named after their father and Mr. Duncan’s mother, Velma Twomey Duncan.

Pioneer of Pinot Noir.

Walter Schug was a native of Germany’s Rhine River Valley and grew up on a wine estate in Assmannshausen. Schug worked his first grape harvest in 1953 and apprenticed at several historic wine estates in the Rheingau region of Germany.

In 1959, after finishing his studies with a diploma in viticulture and enology at the German wine institute of Geisenheim, Schug left for California. He spent a year expanding his knowledge while working at a winery and taking extension courses at the University of California, Davis.

Two years later he returned to California for good, with his wife Gertrud, to work as the assistant superintendent at California Grape Products Corp. In 1966 Julio Gallo asked him to be the E. & J. Gallo Winery’s head of grower relations and quality control for Northern California.

By 1973, Schug was sought out by Joseph Phelps to help establish Joseph Phelps Vineyards in Napa Valley. Schug would spend 10 vintages as vice president at the Phelps winery.