These days, you can't expect corporate radio to not play programmed commercial hip-pop material. It's like that nation wide. These radio stations are pretty much all owned by either Clear Channel, Infinity, or Emmis...
...but still, it aint as bad as you think. Stations like KDAY, Power106, and 100.3TheBeat still play locals. I still hear all the classic shit, and also I've heard new stuff from Warren G, to Bishop Lamont, Kam, Sly Boogy, Crooked I, WC, Alkoholiks, Mitchy Slick (SD), Dirty Birdy, DPGC, Ras Kass, Game, Suga Free, Dilated Peoples, DJ Quik, etc. I know all those names aint underground artists, but they are still locals.