From Babylon, it's a short hop south over the bridges to Robert Moses on Fire Island. After you cross the last bridge, travel easterly to parking lot 5. Follow the path towards the Lighthouse, and then to the beach. There is a daily fee per carload. If you have a National Park Pass, http://www.store.usgs.gov/pass/senior.html you can use it to get in.
-------------------- We are the People our parents warned us about!
According to that link that you provided I can use my senior pass issued by the USDA Forest Service that I use in the White Mountain National Forest here in New Hampshire. Knowing how far reaching my pass can be is certainly a comfort and an excellent reason for seniors to get one. Thanks.