300 Entrada Dr Novato, CA 94949 415.883.0388 open 7 days a week
They have a little bit in a lot of scales, so if you're looking for garden rail or HO or O, you may want to venture in if you're rolling up highway 101 and have a little time.
Don't expect a TRAIN SHOP amount of product, however. This is a shop with more than just trains on the mind. It features a huge dollhouse and Christmas building selection, so the trains are just part of the scene.
They also had a rash of thefts and adopted a card entry membership to avoid being a target. So, be prepared to be stopped at the door when you enter and asked for your membership card. If you don't have one, the process is painless - a mere showing of a drivers licensee so they can make a card for you.
All in all, it's worth checking out.