This road is designated by the State of California for its beauty and has been given the "Scenic Route" label for many reasons. The flora, rolling hills, and lush vineyards are a few.
The CA-12 between Sonoma and Santa Rosa is called the "Valley of the Moon" and runs through several smaller communities like Boyes Hot Springs, Agua Caliente, Kenwood, and Oakmont.
Travel can be slower along this route because the route does go through these smaller towns and because of the many wineries and vineyards in the area. This area is congested with many tourists on the weekends.
There are nice wide open vineyards and pastures between the cities and it is a pleasant drive when traffic is light.
If traffic does get heavy, stop off at one of the many various State and County parks for a beautiful scenic break, climb up on the mountains and get views that are unsurpassed in beauty.