We have gone to Acadia every year (for the past 13 years) for vacation and stay at Hadley's point campground on the north side of Mount Desert Island. They have a website at Hadley's Point Campground Bar Harbor. It is a very neat, clean park with both shaded and open sites, lots of hook-up sites, and very family oriented. There are campgounds in the National park but they have limited facilities and we have never stayed there. As stated above millions of people do visit Acadia every year. We have found that June is the least busy month and if you like fall camping Sept/Oct is not very crowded. Beware that if you go in the spring you will hit the very unpleasant black fly season!