If ya do decide to go and catch California Northern, I strongly recommend the Maxwell Turn. It takes off out of Davis around 8:30 - 9 and runs between Davis and Cortena.

Also, some quick sleuthing around yielded some particularly interesting locations along the Maxwell Turn's route--

Old East Davis...maybe there's a good shot from the parking garage.
Wide open spaces just north of Davis.
Woodland Junction
The largest RACO cantilevers I have ever seen...these are outside Yolo.
A truss bridge in Yolo.
The Maxwell Turn switches here at Zamora...oh, and there's also Teardrop bells, bring a tape recorder for full effect.
A nice stand of Gum Trees in Dunnigan.
A nice thicket and trestle just outside Maxwell
The Maxwell Turn tends to switch crews with the Corning Flyer at Cortena Siding.

Be aware that because I have a lean towards vintage signals and bridges my recommendations may be somewhat skewed. Hope this is of some help!