Unfortunately, Chris, you would be horrified to see the condition of the national forests within easy driving distances of major urban centers, especially in California. Sadly, the same is true of the coast of Northern Baja -- there is a shocking amount of trash along the beaches, and much of it is local in origin. (Some of it is flotsam and jetsam -- I never can remember the difference between those two things.)
If you look long and hard enough, though, you can find pristine boondocking in the West, especially east of the Sierra crest and into the Basin and Range territory. I was especially impressed with the public land in Utah -- the boondockers out there were much more well-behaved, for some unknown reason. Obviously, that's just my subjective impression -- I don't have hard data to support that opinion.