You should be able to find some Uroctonus mordax, and a few other species in Marin county.
Find yourself someplace that isn't heavily developed, nice open spaces with rocks and logs, or foresty areas. Flip rocks, and roll logs. You should find something. Just remember not to over harvest the area you find them in, and put the rocks and logs back where you found them as best you can. The moisture under the rocks is a vital micro climate for many different animals, and you can always go back later and flip the same things again.
