High in the Mayacamas Range, at an elevation of 1,700 feet above the Napa Valley floor, are Spring Mountain and the Robert Keenan Winery and vineyards. This area was first identified as prime vineyard land by Peter Conradi in the late 19th century when he planted 100 acres of terraced vineyard in Zinfandel and Syrah grapes. The Conradi Winery operated until Prohibition when the vineyards and winery fell out of use. In 1974, Robert Keenan purchased 180 acres of forest on the defunct Conradi Winery site. No vines remained. Only the crumbling walls of the former winery and a few old broken tanks told of its history, but Robert was certain the mountain top vineyards would be perfect for an estate winery. He replaced tree stumps and rocks with rows of Cabernet and Chardonnay, hired an engineer to redesign the original winery structure, and brought in a contractor to begin construction. The winery was made operational just in time for the harvest of 1977. From that time on, Keenan has earned a great reputation for producing wines of intense character and renowned acclaim.