Welcome to the GardenWeb, Joe. Your location is similar to mine except for the elevation. My son lives in Magalia with identical conditions to yours. He grows a wonderful garden of ornamental plants, marvelously varied. Don't think you are limited to a ground cover of some type. Al

What is your zone? There are many acid loving plants, and the sunset Western Garden book has them all. Ferns, Camelias, Gardenias, Hydrangeas and azaleas come to mind.

I spent many days tromping through the Sequioas with my dad, and loved the little flowers and ferns that happily grow under the shade of those giants.

I have the opposite problem! Alkaline soil and mostly full sun!

We do have two groupings of pines on our property, and NOTHING native grows under them. Just rocks and pine needles! A picnic table is planed for one area. Maybe you could soften your yard with conversation chairs or benches and rock paths? There is one silver leafed shrub among our pines, but I don't know what it is.

Good luck! Beg, Borrow, or Buy a copy of The Sunset Western Garden Book!

A really easy plant in dappled sun or some shade are Hellebores. You only need to buy one, because they reseed enough you can transplant the seedlings around. Deer don't like them. Hellebores have pretty foliage, and small flowers that are shaped like umbrellas in late winter/early spring. Maintenance consists of going out once a year in late autumn and tugging off the old foliage, though it is not necessary.

I would also look at a CA native plant site, they will likely have good suggestions.

Here is a link that might be useful: Las Pilitas CA Native Plant Nursery.