Santa Rosa and the whole Petaluma area is awesome for herps haha! But yea, I'm planning on heading to Blithedale Summit on the foothills of Mt.Tam. Apparently lots of herp fuana like Charina and Cal-Kings, AND apparently zoanat.
Heres a link with the herp species list of that open space:
http://www.co.marin.ca.us/depts/PK/Main/mcosd/os_park_04.asp