(a)Name. The name of the viticultural area described in this section is "Sonoita."(b)Approved maps. The appropriate maps for determining the boundaries of Sonoita viticultural area are seven U.S.G.S. maps. They are titled:(1) Benson Quadrangle, 15 minute series, 1958.(2) Fort Huachuca Quadrangle, 15 minute series, 1958.(3) Elgin Quadrangle, 15 minute series, 1958.(4) Lochiel Quadrangle, 15 minute series, 1958.(5) Mount Wrightson Quadrangle, 15 minute series, 1958.(6) Sunnyside Quadrangle, 15 minute series, 1958.(7) Empire Mountains Quadrangle, 15 minute series, 1958.(c)Bouldary -(1)General. The Sonoita viticultural area is located in Arizona. The starting point of the following boundary description is the summit of Mount Wrightson (9,543 feet) in the Santa Rita Mountains.(2)Boundary Description - (i) From the starting point southeastward in a straight line for approximately 24 miles, to the summit of Lookout Knob (6,171 feet) in the Canelo Hills.(ii) From there in a straight line eastward for approximately 10 miles, to the summit of Huachuca Peak (8,410 feet) in the Huachuca Mountains.(iii) From there north-northwestward for approximately 21 miles in a straight line to the summit of Granite Peak (7,413 feet) in the Whetstone Mountains.(iv) From there west-southwestward in a straight line for approximately 26 miles, to the summit of Mount Wrightson (the point of beginning).T.D. ATF-189, 49 FR 43054, 10/26/1984