As you leave the ride-start and bike through Fairfield, don't be surprised if you see a large plane in the sky to the south; you are only a few miles from Travis Air Force Base. 

In short order you will arrive at Mankas Corner and will turn right into the rural Gordon Valley.  I love biking through the Gordon (photo left) and Wooden (photo right) Valleys; the roads, bordered by vineyards, are picturesque and quiet. 

The 55 and 96 mile rides separate at the junction of Wooden Valley Road and Highway 121.

Centurions then will have a moderate climb and descent into the Napa Valley.  Don't be surprised if it is significantly cooler in the Napa Valley than at the ride start.  I always bring a windbreaker on this ride, as micro-climates in these multiple valleys often vary considerably.  At the eastern edge of the city of Napa you arrive at Rest Stop #1.  Riding through Napa is no treat!  CAUTION:  traffic is heavy, and vehicles often turn directly in front of you.   Fortunately Trancas Street is relatively short.  

 

Traffic becomes minimal as you traverse Redwood Road (photo left) and start the gradual climb up Mt Veeder Road (photo right). 

I find this section especially enjoyable (a real favorite!):  redwood trees provide a forested appearance, the climb is easy, and the area is isolated. 

View of the Napa Valley is lost until, after a fast descent (CAUTION:  it is easy to go too fast!) down Oakville Grade,  you return to the Napa Valley and enter Oakville.  The left turn onto Highway 29 is hazardous:  traffic is very heavy; waiting for traffic can take several minutes. 

You next arrive at Rest Stop #2 at the well known Oakville Grocery. 

Vineyards line Rutherford Cross Road (photo above) as you quickly cross the Napa Valley.  A quick right-left jog on the Silverado Trail takes you onto Highway 128.  CAUTION: boat trailers (often almost as wide as the lane!) frequent Highway 128; I strongly recommend a mirror.  A gradual climb brings you to Conn Dam; I often stop in front of the spillway to nibble and enjoy a break.  Lake Hennessey then appears on your left.  Moderate climbing through narrow Sage Canyon (Sage Creek on your right) ends at Lower Chiles Valley Road.  A few more miles takes you to Moskowite Corner and Rest Stop #3 (on your left), where the 55 and 96 mile rides rejoin.  

Terrain along Highway 128, on the course of the Davis Double Century, generally is gently rolling.  One exception is "Cardiac Hill" (don't worry: you will be descending), a fast and mildly curvy section which brings you down to Lake Berryessa.  Another brief descent, just after Monticello Dam, starts an easy ride along Putah Creek.  Then arrive at Rest Stop #4 (I usually don't stop here).

Next, turn south onto Pleasants Valley Road. 

Almost immediately Lake Solano Park will be on your left (restrooms, shady picnic tables). 

I always enjoy the cruise down Pleasants Valley Road (photo left), which is rustic, quiet, and picturesque. 

At the termination of Pleasants Valley Road, several short roads return you to Fairfield and ride's end.