NAPA VALLEY, Calif. — As I floated 2,500 feet above this storied wine-producing valley in a hot air balloon, all I could see below was a vast mosaic of greens. Greens in every shade — from palest lettuce to soft sage to vivid emerald. Soaring over the Mayacamas Mountain Range, a tantalizing view of Mount St. Helena (not to be confused with Washington state’s Mount St. Helens) loomed in the distance — a green silhouette