Mount Desert Campground near Bar Harbor ME

Note the cruise ship schedule for Bar Harbor - some of them dump 4000+ extra people in town for a day or two. I would plan other activities those days

Bar Harbor Cruise Ship Schedule 2018 (PDF)

We encountered this visiting Portland last September. Our favorite quiet restaurants were swamped at lunch. Things were back to normal in a couple of days and we know to time it better next time.

As said, lots of things to do, like Whale, Seal, Seabird watching cruises, great hiking & sight seeing in Acadia NP, drive to the top of Cadillac Mountain, (very early) for spectacular sunrises, not to mention my favorite, Lobster bisque, Lobster Rolls, Lobster Stew, Lobster Mac & Cheese, Lobster Dinners, & home made Blueberry Pie. ;)
If you're talking about Mount Desert Narrows RV Resort, I'm sorry I can't help you as we wont be there till September.

Pop-overs at Jordon Pond are a must.

Lots to do in the area. There are free shuttle busses that take you pretty much anywhere you want to go. There are many great hikes , and in July, you'll be able to pick wild blueberries. If you have bicycles, there are about 40 miles of groomed carriage roads ( no vehicle traffic) to explore in the park. In town, many good restaurants and bars and lots of touristy shops. Of course there are a number of lobster pounds. Thrustons has great views while eating. At teh trenton Bridge, there are 3 pounds.

Haven't stayed there - we've always used Blackwoods. Obviously, spend time in Acadia! Here's something fun... It's called "Bar harbor", because of the gravel sandbar that leads from the mainland out to "Bar island". About 45 min before low tide, the "bar" is exposed, so you get about 1.5 hrs that you can walk across the ocean floor, out to Bar Island, for a cool little hike and view back to the headlands. Also, from Southwest harbor, there used to be, not sure now, of a cruise out to the Cranberry islands with a park naturalist on board. ST