(a) Name. The name of the viticultural area described in this section is “Napa Valley.”

(b) Approved maps. The maps showing the boundaries of the Napa Valley viticultural area are the:

(1) “Mt. St. Helena” U.S.G.S. 7.5 minute quadrangle;

(2) “Detert Reservoir” U.S.G.S. 7.5 minute quadrangle;

(3) “St. Helena” U.S.G.S. 15 minute quadrangle;

(4) “Jericho Valley” U.S.G.S. 7.5 minute quadrangle;

(5) “Lake Berryessa” U.S.G.S. 15 minute quadrangle;

(6) “Mt. Vaca” U.S.G.S. 15 minute quadrangle;

(7) “Cordelia” U.S.G.S. 7.5 minute quadrangle;

(8) “Cuttings Wharf” U.S.G.S. 7.5 minute quadrangle; and

(9) Appropriate Napa County tax assessor's maps showing the Napa County-Sonoma County line.

(c) Boundaries. The Napa Valley viticultural area is located within Napa County, California. From the beginning point at the conjuction of the Napa County-Sonoma County line and the Napa County-Lake County line, the boundary runs along—

(1) The Napa County-Lake County line;

(2) Putah Creek and the western and southern shores of Lake Berryessa;

(3) The Napa County-Solano County line; and

(4) The Napa County-Sonoma County line to the beginning point.