Ten miles west of Paso Robles, a stone’s throw from the old Adelaida School House, stands a lone vine, as tall as a man and nearly as thick. It’s one of a handful of survivors, maybe a half dozen in total. They stand, scattered, in a field now mostly given over to mustard, although it borders an old orchard of Paso’s other traditional cash crop, walnuts. These vines are living artifacts, remnants of what was one of the earliest vineyards planted in San Luis Obispo County.