Hi, Mark,
From the Napa area, you have easy access to coastal environments, like Point Reyes, Bodega Bay, or coastal Mendocino County. All of these destinations take you through or near redwood forests, which provide another unique ecosystem. Mendocino is a touristy little coastal town, but in a pretty spectacular location. If you go there, check out McKerricher Beach in Fort Bragg, and Jughandle Reserve. Also in Fort Bragg is the NOrth Coast Brewing Company, with some decent micro brew ales, if you're into that sort of thing.
Heading East from Napa, you can get into the Central Valley of California, which is, once again, a very different sphere. Most of the migrants will have gone North, but there's still a lot to see. The trip from Napa to Davis, via 128, is a fairly curvy road past Lake Berryessa, but it's a nice drive. It should take you about an hour. When you get down into the Valley, look for Yellow Billed Magpies. Be advised that in the Central Valley in June, it's not unusual for daytime high temperatures to reach 38 degrees C, but will probably be less.
Jim
