Support for proposed rules to limit wines using “Napa Valley” to wine makers only in California is growing with organizations that represent numerous California grape growers. It would also include viticultural names when different grapes are added or the winemaking process is completed outside of the state.
Currently regulation allows wineries countrywide to use “Napa Valley” by applying for an exemption that allows them to source grapes from out of state vineyards and use the name of the grapes AVA, as long as the finished wine is sold only in the state where it is produced.
Source: Napa Valley Register, December 2016