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

(b) Approved maps. The appropriate maps for determining the boundary of the Oakville viticultural area are two U.S.G.S. 7.5 minute series topographical maps of the 1:24,000 scale:

(1) “Yountville Quadrangle, California,” edition of 1951, photorevised 1968.

(2) “Rutherford Quadrangle, California,” edition of 1951, photorevised 1968, photoinspected 1973.

(c) Boundary. The Oakville viticultural area is located in Napa County in the State of California. The boundary is as follows:

(1) Beginning on the Yountville quadrangle map at the point where the county road known as the Silverado Trail intersects Skellenger Lane, just outside the southwest corner of Section 12, Township 7 North (T.7 N.), Range 5 West (R.5 W.), the boundary proceeds in a southwesterly direction in a straight line approximately 1.7 miles along Skellenger Lane, past its intersection with Conn Creek Road, to the point of intersection with the main channel of the Napa River (on the Rutherford quadrangle map);

(2) Then south along the center of the river bed approximately .4 miles to the point where an unnamed stream drains into the Napa River from the west;

(3) Then along the unnamed stream in a generally northwesterly direction to its intersection with the west track of the Southern Pacific Railroad Track;

(4) Then southeasterly along said railroad track 1,650 feet to a point which is approximately 435 feet north of the centerline of the entry road to Robert Mondavi Winery (shown on the map) to the southeast corner of Assessor's Parcel Number 27-250-14;

(5) Thence southwesterly S 55°06′28″ W for 3,869 feet along the common boundary between Assessor's Parcel Numbers 27-250-14 and 27-280-50/51 to the southwest corner of Assessor's Parcel Number 27-250-14;

(6) Thence northwesterly N 40°31′42″ W for 750 feet along the westerly property line of Assessor's Parcel Number 27-250-14;

(7) Thence southwesterly S 51°00′ W in a straight line to the 500-foot contour line of the Mayacamas Range in the northwestern corner of Section 28, T.7 N., R.5 W.;

(8) Then proceeding along the 500-foot contour line in a generally southeasterly direction through Sections 28, 29, 20, 29, 28, 29, 28, 33 and 34 of T.7 N., R.5 W. and Section 3 of T.6 N., R.5 W. to its intersection with the unnamed stream known locally as Hopper Creek near the middle of Section 3;

(9) Then along the unnamed stream (Hopper Creek) southeasterly and, at the fork in Section 3, northeasterly along the stream to the point where the stream intersects with the unnamed dirt road in the northwest corner of Section 2, T.6 N., R.5 W;

(10) Then proceed in a straight line to the light duty road to the immediate northeast in Section 2, then along the light duty road in a northeasterly direction to the point at which the road turns 90 degrees to the left;

(11) Then proceed along the light duty road 625 feet, then proceed northeasterly (N 40°43′ E) in a straight line 1,350 feet, along the northern property line of Assessor's Parcel Number 27-380-08 (not shown on the map), to State Highway 29, then continuing in a straight line approximately .1 mile to the peak of the 320 + foot hill along the western edge of the Yountville Hills;

(12) Then proceed due east to the second 300-foot contour line, then follow that contour line around the Yountville Hills to the north to the point at which the 300-foot contour line exits the Rutherford quadrangle map for the second time;

(13) Then proceed (on the Yountville quadrangle map) in a straight line in a northeasterly direction approximately N 34°30′ E approximately 1,000 feet to the 90 degree bend in the unimproved dirt road shown on the map, then along that road, which coincides with a fence line (not shown on the map) to the intersection of Conn Creek and Rector Creek;

(14) Then along Rector Creek to the northeast past the Silverado Trail to the Rector Reservoir spillway entrance, then proceed due north along the spillway of Rector Reservoir, then east and northeast along the shoreline of Rector Reservoir to the point where the first unnamed stream enters the Reservoir;

(15) Thence follow the unnamed stream north and northeast to where it intersects an unimproved dirt road at the 1006-foot benchmark;

(16) Then proceed in a straight line approximately .6 mile due west to the intersection of an unnamed stream, then follow said stream downslope to the 500-foot contour line, and along that contour line northwesterly through sections 18 and 13 to the intersection of the contour line with the southern border of Section 12 in T.7 N, R.5 W.;

(17) Then proceed in a straight line in a westerly direction to the intersection of Skellenger Lane with the Silverado Trail, the point of beginning.