Yes, Nickerson State Park in Massachusetts allows RVs. The park offers many campsites that can accommodate RVs, campervans, and trailers. Facilities include restrooms, showers, and dump stations. The park's beautiful setting amidst forests and freshwater ponds makes it a popular destination for campers. Please note that some sites may have length restrictions, so it is essential to verify the site's suitability for your RV before making a reservation.