Not sure what type of camping you like, but this is a good place to start.CampMaineBTW someone suggested Baxter State Park. It is one of Maines best, but they do not allow dogs and possibly your Class C because of it's width.
Just in case your 3500 long bed is DRW the following is from the Baxter State Park rules.5.1 No vehicle over nine (9) feet high, seven (7) feet wide, or 22 feet long for a single vehicle or 44 feet long for combined units may enter the Park.
46 was repaved a few years ago, but after last winter who knows. 179 is a little more direct, the last time I drove it was last year and it did have a few rough spots, but was not bad at all.