A century after the Star's report, in 1983, the Howell Mountain American Viticultural Area (AVA) became one of Napa Valley's first official sub-designations. Where rivers, creeks, and property lines commonly define an AVA, Howell Mountain's boundaries are defined by a 1,400-foot elevation as the lowest point and the highest vineyards at 2,500 feet above sea level. The vines share the mountain with pines, oaks, madrons, and coast redwoods.