Patos Island Marine State Park is a 207-acre marine park with 20,000-feet of saltwater shoreline. The island is owned by the federal government and is administered by the Bureau of Land Management's Wenatchee Office. The Washington State Parks and Recreation Commission operates a small campground facility at Active Cove near the west side of the island, maintains a 1.5 mile loop trail, and has two offshore mooring buoys.
The park is open year round for camping and day use.
Patos Island is incredible. A little bit hard to get to, the cove on Patos boasts strong currents that require you to anchor with care if not using one of the few mooring buoys. Some of the campsites are rather exposed while others are well tucked into the woods.
The walk to the Patos Lighthouse is easy, short, and a must do. My favorite is going to the lighthouse for sunset. If you're lucky enough to be there when the lighthouse is open for tours you'll get a quick glimpse into the history of the islands.
This is one of the northern most islands in the San Juan's so don't be surprised if the US Coast Guard is lingering about. This was one of my stops on a two week sea kayak adventure in the fall.
Like all of the marine state parks in Washington, this site is well maintained. You will find clearings for pitching your shelter, a picnic table and relatively clean vault/pit toilets. There is also great signage so you are certain of where you are.
These sites are remote, so don't expect many visitors and be sure to soak up the incredible views (especially around sunrise and sunset).