San Francisco is the main gateway to the Wine Country, which lies due north of the city. Driving is the best way to explore this region. The easiest route to southern Napa and Sonoma counties is to head north across the Golden Gate Bridge on U.S. 101 and east on Highway 37 to Highway 121. Follow signs for the towns of Sonoma (45 miles from San Francisco) and Napa (about 52 miles). Remain on U.S. 101 if your destination is Santa Rosa (55 miles) or Healdsburg (70 miles).
By car. Well-maintained roads zip through the Napa and Sonoma, and scenic routes thread through the backcountry. Distances between towns are fairly short, and you can drive from one end to the other of either valley in less than an hour if there's no traffic. The Mayacamas Mountains divide Napa and Sonoma, though, and only a few winding roads traverse the middle sections, so the drive between valleys can be slow. The quicker connector is Highway 121, which runs east–west between southern Napa and Sonoma counties. The far-northern route—from Highway 128 just north of Calistoga, take Petrified Forest Road and Calistoga Road to Highway 12—has a few curves but also great vistas.
By public transportation. Visitors without cars can take van, bus, or limo tours from San Francisco. Taking public transit to hubs like Sonoma, Napa, Santa Rosa, and Healdsburg can be time-consuming, but once you arrive at your destination, you can take advantage of taxis and other options.