I'm right outside of Bangor, in Carmel. There's a 3D range at the Old Town Archery shop, along with indoor leagues there during the winter. I'm not sure what's going on down in the Castine area, but I've got a few targets out back you're welcome to come over and shoot.
Be sure to join the Maine Traditional Archers while you're up here. It's a fine organization and we have several shoots each year, including the State Traditional Championships, August 17th in Durham. This is near Freeport and there's plenty of shopping at LLBeans, including a new Hunting/Fishing store. #0 minutes or so down the road is Portland, which has a new Cabelas at Scarborough.
PM me for any details or with any questions you may have. Oh, bring long underwear! This isn't the islands, Brah! It gets cold up here, lol, but you're going to a fine school.