Any good sites in Maine?

My family is vacationing in Maine in a week and I'd like to get some advice on where I can go rockhounding for the pretty rocks. I've done some research, and Mt Apatite Park is on my list so far, but I'm looking around to weigh my options. I'm from Georgia and I'm really spolied with what we have to offer, but at the same time, we have salted tourist traps all over the place, some of them portray themselves as unsalted very well....

I'd like to find a preferrably free/nominal fee site either with facilities, or "bring your own toilet paper". Any help would be greatly appreciated!

Thanks -