If you're renting a car, I'd drive up to Point Reyes National Seashore for a day. Lots of nice hikes and good coastal viewings. (Although I'm biased as a birdwatcher) I worked east of Oakland for a summer and up in NoCal for a few summers, and enjoyed Pt. Reyes on the weekends, although in January it could be cold and windy. I also took that same train route twice before. The empire builder was nice, lots of room and most of the people are older travelers. (sneak on your own booze though). The Coast starlight train is usually packed with people moving up and down the coast. Get good seats and stay in them! Don't get caught in the lounge car for awhile and lose your seat. Also, my favorite beer is Lagunitas IPA, which is brewed in Petaluma I believe. Have fun