To find scorpions, you must locate undisturbed habitat. The only portions of HB where you have a shot at finding any are generally gated off or protected from collection.
Southern california has quite a few species, especially in our deserts, but there's quite a bit of diversity here in the coastal regions, as well.
Anuroctonus pococki- Found in scrub, but much more common in chaparral habitats. Likes dry sandy clay hillsides. Often occurs alongside aphonopelma.
Paruroctonus silvestrii- Found in riparian, oak woodland, coastal scrub. prefers sandy areas. Burrower, but also takes refuge under stones and wood.
Serradigitus gertschi- Found in dry talus-strewn slopes or cliff faces. Prefers to hang upside-down, or vertically in crevices. lithophilous.
Pseudouroctonus williamsi- Found in coastal scrub. Doesnt burrow, but scrapes under rocks. Fairly common where found.
Pseudouroctonus minimus- Found in coastal scrub, oak woodland, broadleaf forest. more comman than williamsi.
Vaejovis puritanus- Chaparral and coastal scrub. More common in true chaparral or savannah habitat. Likes drier areas, much like its close relative P waeringi, which is only found in desert habitat.