Paso Robles Wine Producers
There are also a lot of threads on the board about it already.
Like this one that went on forever about ones to avoid:
Off the top, many of them are dry-farmed and use native yeasts.
Ambyth is Biodynamic.
Tablas Creek (some dry farmered like the Mourvedre on scruffy hill) all native yeasts and organic.
Dante Dusi Zinfandel is dry farmed but not organic. They use it at Turley, Four Vines, and the family J Dusi.
Pipestone is organic if I recall.
but Pasowine.com will have all the info you need.
You can also check out my site for a map to all the local wineries
www.pasotours.com. I will look into it and add organic and biodynamic info to the links.