John Duffy, a nuclear engineer turned grape grower and hotelier who developed Vintners Inn, the home of famed restaurant John Ash & Co., died June 20 of an unexpected illness. He was 72.

"He was a brilliant, fascinating man," said his wife, Cindy Duffy of Santa Rosa. "He made a lot of contributions to Sonoma County."

Duffy moved to Santa Rosa in 1976 after retiring at age 35 from a career in nuclear engineering. He and his first wife, Francisca Van Lith, bought a 50-acre prune orchard on Barnes and River roads. The couple, who later divorced, tended the farm for a few years and Duffy became active in the Sonoma County Farm Bureau before replacing the fruit trees with grape vines.

In 1983, he built the 44-room Vintners Inn on the property. The upscale lodge nestled in vineyards later became home to John Ash & Co., a restaurant that helped pioneer Wine Country cuisine. Duffy sold the property in 2000.

Born Feb. 26, 1942, in New York City, Duffy graduated with an engineering degree from SUNY Martime College and later received master's degrees in both nuclear and mechanical engineering.

He worked for the Atomic Energy Commission, Bechtel Engineering and Pacific Gas & Electric before helping start EDS Nuclear, a consulting firm where he served as senior vice president.

Upon his retirement and before coming to Santa Rosa, he took several voyages on a sailboat along the California coast.

Cindy Duffy met her husband while working first as an assistant and later as general manager at the inn. The couple had been married 20 years.

She described Duffy as a well-rounded person with a logical, practical mind.

"Before the age of the Internet, you could ask John anything," she said. "He was like Google. He was knowledgeable on just about every topic there was: farming, viticulture, business administration, politics."

She said Duffy loved the ocean and the couple made regular visits each year to The Sea Ranch. He also enjoyed photography, racquetball, kayaking and bicycling, as well as following current events.

Among others, Duffy is survived by his wife and his sister, Pat Duffy of Santa Rosa.

There will be no public memorial service at Duffy's request, though his wife plans to hold a private gathering to celebrate his life.