APM: 7 Location: SR 121 and SR 12, Sonoma Cty Reassurance shield as 12 joins 121. The highway keeps 121’s postmiles. APM: 9 Location: SR 12 and Ramal Rd, Sonoma Cty Reassurance shield a couple miles later. APM: NAP/3 Location: SR 12 and Stanly Ln, Napa A few miles later we’ll cross into Napa County and enter the … Continue reading California State Route 121, SR 12 to SR 12/SR 29