Plum Island is a barrier island off the coast of Massachusetts, and it is not open for public camping. The island is home to the Parker River National Wildlife Refuge, which is a protected and restricted area. However, the Plum Island Airport is located in Newburyport, Massachusetts, and is not on Plum Island. It operates under specified hours. There are nearby campgrounds and RV parks on the mainland where you can stay and enjoy the surrounding area. For alternative camping options, you can explore Hipcamp.