Best Biking Maps for Sonoma Valley & Marin County | Cycling Routes

Question
Do you have any suggestion for biking maps for the Sonoma valley in California.  We are a group of ten going biking for a week and like to ride about 50 to 100 miles a day.
Thank you

Answer
I am not from that area so I don't know a lot about it.  When I biked through that area, I found a bicycle map of the north bay area.  It covered parts of Sonoma and all of Marin Counties.  I am sure there are several maps available.  The north bay bicycle map that I got was sold at a bike shop.  

Happy cycling
Robert
http://www.theslowlane.com