From Boston take I-95 north to Augusta, Maine, then Route 3 east to Ellsworth, and on to Mount Desert Island. For an alternate route, continue on I-95 north to Bangor, Maine, then take Route 1A east to Ellsworth. In Ellsworth, take Route 3 to Mount Desert Island.
Direct flights from Boston's Logan Airport land at the Hancock County Airport, 10 miles from Acadia National Park. National airlines serve the Bangor International Airport, about one hour from the park. Car rentals are available at both airports.