If you do plan to ride more on the street, the Michelin
Deserts are really good. The rear is a 140. It has the same casing as the Baja mentioned above, but it has shorter and much stouter tread blocks. I've gotten over 1200 miles on a rear with a mix of pavement, very high speed forest circus/bureau of land mismanagement dirt/gravel and desert races (hare and hounds). They ride down the road smoother than any other tire that I have tried (Dunlop 606 & Michelin
Baja) but the price is hard to swallow. However, I usually destroy a rear tire in under 500 miles, so I justified the expense that way. I should also say that by 1200 miles, I still had tread left (about 40%), but the tire had gone through enough heat cycles that it had baked itself into a black stone. Off the pavement all it would do is spin violently at that point in it's life. The front works equally well. The only bad thing about the Michelin DOT tires (Desert or Baja) is that they are terrible in anything that even remotely resembles mud. Or wet grass! But in SoCal, that probably isn't much of a concern. If you still plan to ride more dirt than asphalt, go with the Dunlop
606. Great dirt tire that is still DOT legal. Tall knobs that don't chunk easily in the rocks. But not as good on the asphalt as the Michelin Desert, at least in my opinion.