Sonoma Valley AVA per the ATF
The Sonoma Valley viticultural area has a long history of grape growing and wine making. In 1825, the first grapes were planted in Sonoma at the Mission San Francisco de Solano. In 1834, General Mariano Guadalupe Vallejo expanded these plantings. In the 1850's, the first major plantings of Vitis vinifera in the United States were established in the Sonoma Valley area. By 1900, there were approximately 4,000 acres of vines in the Sonoma Valley. The area has continued to be a center for grape production and wine making. Thus, ATF feels the viticultural area meets the requirement of 27 CFR 9.3(b)(1) that the name of the viticultural area is locally or nationally known as referring to the area specified in the viticultural area proposal.
Several persons testified at the public hearing that the proposed boundaries reasonably delineate the area historically known as "Sonoma Valley." Based on the record of the rulemaking proceedings, ATF feels that the boundaries described in 27 CFR 9.29 delineate the area historically known as Sonoma Valley, as required by 27 CFR 9.3(b)(2).
Geographical Features
Under 27 CFR 9.3(b)(3), a viticultural area must possess geographical features which distinguish the viticultural features of the area from surrounding areas. Based on the record, ATF believes that the Sonoma Valley viticultural area is distinguishable from the surrounding areas because of its climate.
The viticultural area, located in the southeastern corner of Sonoma County, receives less rainfall than other portions of Sonoma County north of the city of Santa Rosa. In addition, the Sonoma Mountains, ranging along the western border of the viticultural area, prevent the heavy fog often found in the area of Petaluma from intruding into most of the Sonoma Valley area. These same mountains along with the Mayacamas Range on the eastern boundary of the viticultural area geographically isolate the area from surrounding areas. This geographical isolation and the proximity of the San Pablo Bay on the southern end of the area combine to moderate the summer and winter temperature extremes in the valley.
Boundaries
Much of the hearing testimony was on the proposed boundaries with controversy arising over the boundaries in the northeastern and southeastern corners of the viticultural area. One vineyard owner felt that the northeastern corner of the Sonoma Valley viticultural area should be part of a future viticultural area which he planned to propose. He stated that he did not object, however, to the proposed Sonoma Valley boundaries as long as the approval of the boundary would not preclude a future viticultural area from partially overlapping that corner of the Sonoma Valley viticultural area. ATF does not object to a proposed viticultural area solely on the grounds that it may partially overlap another area. Each area must be judged individually on the criteria required in the regulations. Each area must meet the same requirements concerning the area's proposed name and the presence of distinguishing geographical characteristics. In addition, the establishment of viticultural areas is an evolutionary process. ATF will continue to consider any new information concerning viticultural areas. The boundary in the northeast corner of the Sonoma Valley viticultural area is drawn along the peaks of the mountains surrounding Sonoma Valley. ATF feels that this boundary delineates an area which meets the requirements for a viticultural area. This area includes the area traditionally known as Sonoma Valley and which possesses generally similar geographical features which distinguish it from the surrounding areas.
The boundary in the southeastern corner of the viticultural area was controversial because it conflicted with the previously proposed Napa Valley viticultural area by including a small *59238 portion in Napa County bounded by Los Amigos, Duhig, and Ramal Roads. ATF subsequently approved the Napa Valley viticultural area (including this disputed portion) using the Sonoma County-Napa County line as the boundary (46 FR 9061). This boundary is based on historical evidence presented at the Napa Valley hearing indicating that that part of Napa County has been traditionally known as part of "Napa Valley." ATF does not feel that there is sufficient evidence indicating that any portion of Napa County has been traditionally considered a part of "Sonoma Valley" or any portion of Sonoma County has been part of "Napa Valley." Each viticultural area has been traditionally identified with the county of the same name. ATF is establishing the county line as the common boundary between the two areas. Therefore, the area in Napa County bounded by Los Amigos, Duhig, and Ramal Roads and proposed as part of the Sonoma Valley viticultural area will remain in the Napa Valley area and not become part of the Sonoma Valley area.
At the public hearing a commenter suggested that the final regulations should allow property owners whose property is divided by the viticultural area boundary to choose whether their property, in its entirety, is in or out of the viticultural area.
ATF believes that although there may be some viticultural similarities between an area in Napa County and an area in the Sonoma Valley viticultural area, the area in Napa County does not meet the requirements of 27 CFR 9.3(b)(1) since the area has not been known as Sonoma Valley.
Also, property located outside the boundaries of a viticultural area may not be included in that viticultural area even if it is part of a larger parcel of property divided by the viticultural area boundary. ATF believes that to hold otherwise would make the regulations meaningless and possibly mislead consumers of wines labeled with a viticultural area appellation of origin.
Finally, evidence was presented at both the Napa Valley and Sonoma Valley hearings indicating that the United States Geological Survey (USGS) maps are inaccurate and are different from the actual county line as drawn by the tax assessors of both Napa County and Sonoma County. ATF is using the actual Napa County-Sonoma County line as the eastern boundary of the Sonoma Valley viticultural area regardless of where the USGS maps place it. ATF normally uses USGS maps because they are generally available throughout the United States. However, in this case, ATF is using the Sonoma County tax assessor's maps as the approved maps defining the Sonoma County-Napa County line.
