In addition to the three main islands, the San Juans  contain a myriad of smaller ones, including some islets that only appear at low tide. Shaw Island  is served by the ferry system but has limited services.
Of the remaining islands, only Blakely Island  has a store and marina. The rest are either marine state parks, part of the San Juan Islands National Wildlife Preserve, or priv
The state ferry does not stray beyond the four most popular islands (San Juan, Orcas, Lopez, and Shaw), and access to the others is generally by private boat or floatplane.