I don’t know if this is a “trail,” per se, but I found it on Wine Country Getaways. The site is, as expected, primarily focused on Sonoma and Napa, as well as other Wine Countries throughout the U.S. I found a couple of Paso Robles trails, but they were all incomplete. This may be incomplete as well, but I had to put it up! Unfortunately, there’s no map or link to an appropriate site on Wine Country Getaways, so I’m just putting in the links to the six wineries that it described. As I indicated before, there are a couple of overlaps on the wine trails.
West of Highway 101
East of Highway 101