Napa Wineries list

[TheEngineer]

That might be a tough thing. I'm not aware of anything that has ALL of the wineries in Napa as one, many of the lists that you will find are more like paid advertising or tour lists or of people's favourites. The closest I think you will get is from the Napa Valley Vintners which is their local trade association. The website is:

http://www.nvva.org/wineries/