Ann Colgin’s rocky east-facing Tychson Hill vineyard, just north of St. Helena on the west side of Napa Valley, has a long and celebrated history. It derived its name in 1881, when it was purchased and planted by Josephine and Joseph Tychson. Not long before that the land had been owned by Charles Krug, one of the pioneer winemakers of Napa Valley and founder of the eponymous winery.