We'll assume the leash is required.

The short answer: it depends entirely on which island. But unless it’s a designated dog beach or a national park with specific off-leash areas, assume leash laws apply. Many popular islands (like those in state parks or national seashores) ban dogs entirely in summer or restrict them to paved areas.

If you’re planning a trip, check the specific island’s website or call the ranger station. Don’t rely on “I saw someone else let their dog run.” That person might be breaking the rules and risking a fine.

And even where dogs are allowed, they’re usually required to be on a leash no longer than six feet. No retractable leads either—those are banned in most parks.

Save yourself the headache and bring a leash. Or just leave the pup at home with a sitter.