Originally Posted by shotwellian

The stretch of 128 btwn 121 and Silverado Trail (this stretch is known as Sage Canyon) is narrow, with blind corners and sometimes fast traffic. For an experienced rider it's completely fine, but I might avoid it with a new rider. You could do a loop that started in Pope Valley instead (like this: https://ridewithgps.com/routes/19461771) and avoid most of this part.