Yes, and no. Officially you do need a park pass to visit Sand Beach, and if your going to Sand Beach in your car, you will need a Park Pass. That said, you can visit Sand Beach as many times as you want, for free, by taking the free Island Explorer Buses into the National Park.
How can that be, you may be wondering, and the answer is a simple one. If the bus drivers were to demand to see if each passenger has a Park Pass on them, the buses would never be able to run on time. As well, if the buses were required to come to a stop at the fee station along the Park Loop Road, the buses would also not be able to run on time, not only that but what would they do with the people on the bus without passes, they can't just leave them along the side of the roadway.
So to solve this problem, a system was worked out where the buses entering the National Park operate on a honor system, where passengers are reminded they need a Park Pass in order to enter the Park, yet no one checks to see if you actually have a pass. Once the buses arrive at the entrance fee station along the One Way Section of the Park Loop Road, the bus stops just long enough for the driver to give the ranger the number of people on the bus, than the bus moves ahead for the Sand Beach Parking lot not far ahead.
So the bus you need to get aboard at the Bar Harbor Village Green along Main Street is the Sand Beach bus. The first stop the bus makes is at Sieur de Monts Spring, to get off at the Precipice you must ask the driver to let you off there, the bus than passes through the fee station and stops at the Sand Beach parking lot, and than it stops at the Thunder Hole parking lot and gist shop.
