Skagit Island Marine State Park is a 24-acre marine camping park in Skagit Bay. The island is forested with occasional meadows, rock outcroppings, attractive beaches, and a land trail.

The park features primitive campsites and a vault toilet. Gas stoves are recommended. No fire stoves or firewood are available. There is no potable water or garbage service to the island. Visitors must pack out what they pack in.

Overnight vehicle fees must be paid at the Cornet Bay boat launch.