Plum Island Beach is pet-friendly. Dogs are welcome to join their owners on the beach without a leash from October 15 to May 15. Unfortunately, pups are never allowed on the Plum Island Refuge. The off leash section of the beach is by the lighthouse and Captain's Lady. Dogs are not allowed on the beach from May 15th through October 15th. The parking fee is $10.
The Newburyport side of the beach (north of 47th St) allows dogs in the off season anytime, and Memorial Day to Labor Day before 9AM and after 5PM. On the Newbury side, dogs are “never” allowed. But in reality, residents just follow the same rules as the Newburyport beach. Dogs are not allowed south of Jackson Way in the southern end because that is where the reservation beach starts. It’s a wildlife sanctuary.